Malicious vba code vba: Execute an OS command via WscriptShell object and Run method: VBA-RunPE: @itm4n's “We created a phishing email, with an attached Excel document that contains malicious VBA code that downloads a reverse shell to the target machine. nullwhire; 08:53 PM 07 Oct 2024; 5. Bad guys are always using obfuscation techniques to make the analysis more difficult and (try to) bypass basic filters. We can decode this Base64 code either by going online in our host machine and using an online tool, or we can use an inbuilt tool called “Certutil” in Windows. Name. (Eric Conrad, 2011) Malware can cause damage to targeted systems and can spread through carriers such as files or humans. Modern NLP (Natural Language Processing) techniques have significantly improved, and are However, malicious people could write VBA code to create macros that do harmful things. Automate any workflow This repository is intended to provide access to a wide variety of malicious files and other artifacts. They can be relatively small and are easy to modify or even to If you would prefer not to write a script yourself, a partially completed one has been provided for you; you just have to finish writing the two functions at the top of the script to replicate the VBA code that performs the deobfuscation process. I will discuss how to extract Also there are multiple attributes set that don’t do anything VBA (not ported from VB6). Several malware families are distributed via Microsoft Office documents infected with malicious VBA code, such as Emotet, IceID, Dridex, and BazarLoader. py -i vba_code. The p-code of each line is stored in the order some benign VBA program or is missing completely, while the p-code performs the desired malicious action. martin7777; 07:32 PM 07 Oct 2024; 3. vba: Create a new process via WMI for code execution: WMI_Process_Create2. Why Can Macros Do Potentially Dangerous Things? You might assume that a programming language designed to automate tasks in an Office suite would be fairly harmless, but you'd be wrong. At BlackHat Asia we released Evil Clippy, a tool which assists red teamers and security testers in creating malicious MS Office documents. This is why, in 2023, Microsoft took steps to force users to “unblock” VBA files downloaded from the internet. Modern NLP (Natural Language Processing) techniques have significantly improved, and are Malware Analysis - Malicious VBA; Let's Defend Malicious VBA; Hey there! Take this challenge for free. Can yo Link: Malicious VBA — LetsDefend Completing Dynamic Malware Analysis Challenge from LetsDefend. Macros could be used maliciously to drop malware, Vba2Graph - Generate call graphs from VBA code, for easier analysis of malicious documents. doc | python2 vba2graph. I am using a small piece of VBA code to call a command line, which in turn uses Pyomo. Last Updated: 2019-04-23 19:30:14 UTC by Didier Stevens (Version: 1) 3 comment(s) A couple of years ago, we posted diary entry "VBA and P-code": we featured a VBA P-code disassembler developed by Dr. It is a malicious file. Unlike dynamic analysis, static analysis does not involve executing or running the code. Jan 4. - rbearden/macro-malware-detection-with-ml We prioritise doing this for VBA, PHP, Python, and Javascript since malware analysts often find such obfuscated codes in malicious documents and webshells. PPAM file: Rockwell Automation’s RSLogix 5 and 500 software have a vulnerability allowing remote code execution through malicious VBA scripts. G0060 : BRONZE BUTLER : BRONZE BUTLER has used VBS and VBE scripts for execution. However, the tool EvilClippy is fantastic for performing this action and even allows you to replace the uncompiled VBA macro with a non-malicious version of VBA code. VBA's relevance in cybersecurity arises from the potential misuse of its features. Figure 1. Note that my initial suspicious that it was a bot-net installer was based on getting the IP Download the malicious file on your VM. 0 macros will run in the malicious Office document you are Open the Macros section of the Excel workbook (Press ALT + F11) and paste the VBA code. 0 - RingZer0 Team Author: Mr. I am currently working through Malicious Documents: VBA Analysis. Introduction In some cases it is advisable to check what’s inside of an document before opening it. Why Use Them: Syntax highlighting editors make it easier to read the code by coloring different parts of the VBScript Oletools package includes the following tools - oleid: used to detect characteristics peculiar to malicious files. exe Just days ago, Fortinet’s FortiGuard Labs captured a malicious MS Word document from the wild that contains auto-executable malicious VBA code that can spread and install NanoCore RAT software on a victim’s Windows system. 6. , 2014) Zero-day exploits are a type of Search code, repositories, users, issues, pull requests Search Clear. I already solved 1st Malware challenge Malicious Doc. The CDR (Content Disarm & Reconstruction) feature in FortiGate and FortiMail can also neutralize this threat by removing all malicious VBA code. It is just that chunk of VBA code that a number of antivirus tools use to find macros and malicious content in Excel files. When victims open the lure document, Office displays a security warning saying that macros The malware was spread via a Microsoft Word document that contained an auto-executable malicious VBA Macro. If you would prefer not to write a script yourself, a partially completed one has been provided for you; you just have to finish writing the two functions at the top of the script to replicate the VBA code that performs the deobfuscation process. After a period of time it generates a ton of PowerShell code and then executes it. Select 'Zoom to selection ActiveWindow. Other languages would most likely use executables, which cannot be directly and accurately reversed to One of the employees has received a suspicious document attached in the invoice email. When I Malicious VBA Office Document Without Source Code. It runs on Linux, OSX and Windows. While this has some of the markings of being malicious, so does 60% of the code I write. All bypassing techniques which I've found on internet tried to obfuscate code which in my understanding can only try to bypass the signature scanning part. No matter how I analyse it, I can't find a string that corresponds to any URL that would exist This study introduces a comprehensive framework employing P-Code Analysis and XGBoost, a leading-edge machine learning algorithm, to address the issue of malicious VBA macro detection, offering a robust framework that significantly improves upon existing methods. The VBA code then tries to open this XLSX file as a decoy file, this is done possibly to minimize user suspicion about malicious behavior of the VBA macros embedded in the main XLAM file. Cancel Submit feedback Saved searches Use saved searches to filter your results more quickly. The download site is registered in Pakistan and is flagged by Google as malicious. These macros, while integral to automation, have become potent vehicles for cyber-attacks, necessitating advanced detection techniques. In the evolving landscape of cybersecurity, the prevalence of malicious Visual Basic for Applications (VBA) FireEye submitted to VirusTotal a normal Office document carrying malicious VBA code and a counterpart to which VBA purging had been applied, and noticed that detection rates dropped 67%, which clearly shows the efficiency of the technique. What do attackers change the cell name to to make Excel 4. Saksham Bhattarai · Follow. MS-MSDT scheme aka Follina Exploit. Does anyone have these 1st few lines they are able to share please? Ps, im no coder at all! lol Abstract: VBA macro malware has seen a resurgence of use in recent years by malicious actors as a vector to perpetrate cyber attacks. WMI_Process_Create. Malware Analysis Exercises. Visible is only true if the Editor is open/visible. vba: Another WMI code execution example: WscriptShell_Exec. 12. When the user enables the macros in the malicious Excel file, the stager downloads the Meterpreter implant and executes it on the host: a connection is made back to the command-and-control server at 149. sibasec; 04:52 PM 07 Oct 2024; 2. We can create a malicious macro using MS Word which leads to create a doc file contain our malicious code, if any user open that doc file the payload triggred and attacker gets a reverse shell. Going through its code, a “Workbook_Activate()” method is automatically called when the document is opened. Some can analyze a file structure with the intention of extracting macros for further analysis. VBA code Co-authored by Gustavo Palazolo and Ghanashyam Satpathy. It removes the VBA macro PerformanceCache from malicious documents. Left: Known Kimsuky maldocs vs. alphonsejf; 09:44 PM 07 Oct 2024 ; 7. In one such • VBA source code • Even encrypted with password VBA String Expressions Deobfuscation (mini VBA Parser) Auto Execution Triggers AutoOpen, Document_Open, Document_Close, ActiveX, Other Detections VBA Stomping XLM / Excel 4 Macros. Word, Excel), to detect VBA Macros, extract their source code in clear text, and detect security-related patterns such as auto-executable macros, suspicious VBA keywords used by malware, anti-sandboxing and anti-virtualization techniques, and potential IOCs (IP addresses, NOTE: Don’t open on your local environment. 2. concentrated on the compiled version of VBA source code, known as p-code, and introduced a machine-learning-based approach for identifying malicious macro documents. Our method trains a classifier with benign and malicious VBA macros and detects new malicious VBA macros My goal is to recompile malicious VBA macro code to valid harmless Python 3. : In recent years, the number of targeted email attacks which use Microsoft (MS) document files has been increasing. Note that the VBA project version must match the host program in order for the P-code to be executed (see next example for version matching). py [config] [output] (optional parameters) [config] Config file that contain generator information [output] Output filename for the macro -l --list List of all available payloads and evasion techniques -s --split_strings Randomly split strings at parts -x - Figure 2 shows the functionalities of VBA used by malicious macros. This means that you can replace a malicious macro with a “Hello World!” Macro P-code. In particular, malicious VBA (Visual Basic for Applications) macros are often Eliminate and Contact Vendors - Remove all sections of the offending file other than the VBA code, then systematically eliminate ALL code other than the code from the file until you have identified the specific section of code that is cause the anti-virus to flag your file. The malicious macro project that contains the malicious VBA code is password protected so it cannot be viewed by the analyzer. The initial vector is a Word document with instructions Using Notepad++, I safely opened the document to extract VBA Macro strings, then utilized CyberChef to decode the obfuscated content. How did you harden your systems to protect against a malicious Access database? We purchased a code signing certificate so we could use a GPO to only allow signed macros/VBA code to run. In this section, you’ll learn how to access the VBA environment within Excel by enabling the Developer tab, using a keyboard shortcut, and locating existing macros. Once a victim opens the attached document, a VBA Macro or Excel 4. 2. Right: Maldocs abusing Blogspot. The attachment filename is “ 300093. SQL Injection. If the VBA source code is removed, some tools Abstract: VBA macro malware has seen a resurgence of use in recent years by malicious actors as a vector to perpetrate cyber attacks. Suspicious Module Name. vba: Execute an OS command via WscriptShell object and Exec method: WscriptShell_run. Malicious Macro Generator v2. x version will just report what is happening, not perform the malicious actions – with the exception maybe of performing downloads to retrieve data (while it’s there, and you might want to re-run it later). To train these Using malicious VBA code, a payload is uploaded from various sites on the Internet. Provide feedback We read every piece of feedback, and take your input very seriously. However, the MID function was detected in malicious VBA macros until that point, not in XLM macros. A common feature in all the malicious documents we dissected that caught our attention is the existence of four non-malicious VBA subroutines. The code can be run if the user activates macros after opening the file. After a However, to detect malicious MS office documents most researchers have devoted their efforts to using natural language processing methods to extract several features of the VBA code, both in terms Documents considered suspicious during threat hunting exercises which could not be attributed to UNC1151 used a VBA code that is similar to MacroPack’s commercial VBA scheme which was not used in any of the attack scenarios. The VBA macro de-obfuscates the text file to get an XLSX file, this is a non-malicious Microsoft Excel file. io 1- The code first declares a variable “conn” with Dim to create a new instance of ADO object with “ADODB. Automate malicious VBA macro for Word Doc. Macro Malware: One of the most prominent cybersecurity concerns associated with Excel scripting is the potential for macro malware. Sub FitSelectionToScreen() 'To zoom to a specific area, then select the cells Range("A1:I15"). The An adversary may hide malicious VBA code by overwriting the VBA source code location with zero's, benign code, or random bytes while leaving the previously compiled malicious p-code. To the best of our knowledge, our method is the first method to detect new malicious VBA macros with LSI. Malicious macros are a common form of VBA-based cybersecurity threats. xls), and Publisher Streams under the Macros directory are of most signi cance for malicious VBA detection. g. You switched accounts on another tab or window. There are loads of open source tools out there which can be used to perform static analysis, today we are going to be looking OLE An adversary may hide malicious VBA code by overwriting the VBA source code location with zero’s, benign code, or random bytes while leaving the previously compiled malicious p-code. PeStudio tool to extract Strings. VBA macro malware has seen a resurgence of use in recent years by malicious actors as a vector These malicious VBA macros are obfuscated in several ways to evade detection. Does anyone have these 1st few lines they are able to share please? Ps, im no coder at all! lol An adversary may hide malicious VBA code by overwriting the VBA source code location with zero’s, benign code, or random bytes while leaving the previously compiled malicious p-code. Researcher Kurt Natvig wanted to understand whether it’s possible to recompile VBA macros to another language, which could then easily be ‘run’ on any gateway, thus revealing a sample’s true nature in a safe manner. py -c 1 # Generate call graph from VBA code python2 vba2graph. 3 min read · 3 hours ago--Listen. Run the olevba. Runs on Linux, OSX and Windows. 0 Macro is used to execute malicious code that downloads and runs the Emotet malware. This paper analyzes the efficiency of various machine learning models (artificial neural networks, random forest, decision tree, AdaBoost and XGBoost) against the evolution of VBA-based (Visual Basic for Applications) malware over a large period of time (1995–2021). OLETOOLS • • •A: Automatic triggers •W: Any write operation that may be used to drop a payload •X: Any execute operation • An adversary may hide malicious VBA code by overwriting the VBA source code location with zero's, benign code, or random bytes while leaving the previously compiled malicious p-code. Add a description, image, and links to the malicious-macro topic page so that 5. xls, what is the URL hidden in the VBA that isn't www. Structured Query Language or SQL injection is a common cyber threat that allows attackers to manipulate a web application's database by injecting malicious Malicious Visual Studio Code extensions were discovered on the VSCode marketplace that download heavily obfuscated PowerShell payloads to target developers and Multiple packages were hiding weaponized code that deploys stage-two malware ; The malicious intent was very difficult to spot; Software developers, especially those working One example of the latest malicious npm packages is etherscancontracthandler, with five versions identified. The source code in this stream is compressed using the MS-OVBA algorithm [16] and there Attackers use a function to make the malicious VBA macros they have prepared run when the document is opened. This project extracts, preprocesses, and engineers features from VBA then trains SVM, KNN, and RF machine learning models and evaluates how effectively they can detect malicious macros. Can hide VBA macros, stomp VBA code (via P-Code) and confuse macro analysis tools. So open up the text file where you saved the code earlier and remove the text “ powershell-e” from the code and also remove any whitespaces and save the file. Command & Control. The link provided in the popup (tells me, that documents that are stored in a trusted Analyzing malicious Word documents usually focuses on using 2 different types of tools. The malicious VBA code is executed automatically using its “autoopen” function once a victim clicks the button “Enable Content”, as shown in Figure 1. EvilClippy. More information at: https://cerbero. I have obtained all answers except Q3: Analysing sample2. Macro viruses work by embedding malicious code into documents, spreadsheets and other data files. S0268 : Bisonal : Bisonal's dropper creates VBS scripts on the victim’s machine. 1271746A olevba is a script to parse OLE and OpenXML files such as MS Office documents (e. Obtaining Macro Source Code. This abuses an undocumented feature of module streams [MS-OVBA 2. The code is working perfectly, apart from the message in the image below being triggered Write better code with AI Security. . In this campaign, the spam email contains an attach ed file with a . Refer here. Sign-Up & Start Learning. While the VBA macro source code is only stored in compressed form in Office documents, this PerformanceCache caches the decompressed VBA source code in uncompressed plain text form. To get rid of this situation, you need to remove the VBA password from the Word Macros virus file using SysKare VBA Password Remover. I used the awesome tool olevba, a part of the oletools project, that allows you to query VBA macro source code directly from the malicious file on a *nix system using Office macros are very powerful and versatile because they can host VBA code, which is one of the main reasons threat actors use macros. itamarlevy900; In this video I solved the 2nd Malware Challenge of LetsDefend, It's Malicious VBA. Before In a blog post Nov. This could open you up to viral code if you download Word documents with malicious VBA code in them. Pub Date: 2024 DOI: 10. Often, a macro virus can infect your computer by replacing ordinary commands with malicious code. 84. Each executable file created by the corresponding malicious document acts as a dropper for the final payload. Some sandboxes and reversers try to deobfuscate the VBA code as well, but it’s quite a tedious job if done In the evolving landscape of cybersecurity, the prevalence of malicious Visual Basic for Applications (VBA) macros embedded in Office documents presents a formidable challenge. It’s like giving hackers the keys to your digital castle. For instance, they started relying on visual VBA macros as malicious or benign using the K-Nearest Neigh- bors machine learning algorithm, feature selection, and TFIDF where p-code opcode n-grams compose the file features[3]. They also had never been used by any other malicious subroutines or anywhere else in any documents. The VBA code contains a Meterpreter stager. I used the awesome tool olevba, a part of the oletools project, that allows you to query VBA macro source code directly from the malicious file on a *nix system using olevba is a script to parse OLE and OpenXML files such as MS Office documents (e. (Eric Conrad, 2011) It includes viruses, worms, Trojans, and logic bombs. Most streams found here contain metadata on the VBA project itself, bar VBA PROJECT which contains the actual VBA source code. This generated PowerShell code In July 2020, NVISO detected a set of malicious Excel documents, also known as “maldocs”, that deliver malware through VBA-activated spreadsheets. C0011 : C0011 : For C0011, Transparent I am building an energy system model that is using a combination of VBA and Python (Pyomo). Check this out usin This could open you up to viral code if you download Word documents with malicious VBA code in them. Ready to dive into the world of malicious VBA code analysis? Let’s tackle this challenge together! 🕵️♂️ . We have also seen many techniques employed by attackers when it comes to infected documents, such as the usage of PowerShell and WMI to Although obfuscation is related to malicious code detection, little research has been conducted on obfuscation with regards to Visual Basic for Applications (VBA) macros. When the malicious Word document is opened. 3% on 158 Bypassing Malicious VBA Code Hello people. Threat actors insert malicious VBA code in innocent looking documents. We have also seen many techniques employed by attackers when it comes to infected documents, such as the usage of PowerShell and WMI to With increasing quantity and sophistication, malicious code is becoming difficult to discover and analyze. If the VBA source code is removed, some ViperMonkey - ViperMonkey is a VBA Emulation engine written in Python, designed to analyze and deobfuscate malicious VBA Macros. The file set used in our research is comprehensive—approximately 1. xlsm) Congrats on creating your malicious Excel macro which downloads the actual malware and executes it when user opens the excel document. It writes a piece of PowerShell code from a MMG. Select End Sub Flip number signage on selected cells. Scoreboard. Amongst others, Evil Clippy can hide VBA macros, stomp VBA code (via p-code) and confuse popular macro analysis tools. Performing simple text transformations is often enough to deobfuscate malicious VBA code. com?. When a user opens the malicious Word document and enables Macros, the following actions are executed automatically: Extract the 4 strings from the Word document’s “Shapes”. x code. These subroutines appeared in all the samples and were not obfuscated. The file contains several VBA macros, including junk code. un1k0d3r@gmail. Its author, “Taylor Huddleston”, was Hey, I am trying to create a malicious Word file that will open a meterpreter shell when executed and macros enabled. Share. But it turns out Microsoft removed the ability to sign macros/VBA for Access with the . Office Scripts, on the other hand, exist in the Microsoft 365 Macro viruses work by embedding malicious code into documents, spreadsheets and other data files. All of the samples are in a password protected ZIP archive using a password of: infected. Publication: IEEE Access. Note: This is a Beta and needs lots of modifications How it works Combines macro_pack and VBA-RunPE to create obfuscated macro to run from the memory of Word. If the VBA source code is removed, some . 3402956 Bibcode: 2024IEEEA. ). Thanks primarily to efforts by Microsoft to lock down the Microsoft Office applications to prevent malicious VBA code from running, VBA has plummeted as a malware threat. They execute when a user opens a Commented Code and Junk Code: Malicious scripts may contain large blocks of commented-out code or nonsensical, irrelevant code snippets designed to confuse analysts and automated analysis tools. A329!tr. This is why it is very important to only activate content on a file that you trust completely. VBA macro malware has seen a resurgence of use in recent years by malicious actors as a vector Just a quick post about a problem that security analysts are facing daily For a while, malicious Office documents are delivered with OLE objects containing VBA macros. We will use the Basic Static Analysis, it’s done without open/run the file or read the source code and it Like any powerful technology, VBA can be abused by hackers to run malicious code. Malicious actors can embed harmful VBA macros within seemingly harmless Excel files. As soon as a single line of VBA code is entered (or modified), it is compiled into an assembler-like language, called “p-code” (from “pseudo code”) for a virtual stack machine. While the malicious VBA code and the dropped payloads were something we had seen before, it was the specific way in which the Excel documents themselves were created that caught our attention. Bontchev. You signed out in another tab or window. 66 on port 443, using TCP and RC4 encryption. These malicious VBA macros are obfuscated in several ways to deceive anti-virus programs. ppam ”. Inclusion of non-malicious code. - outflanknl/EvilClippy Runs on Linux, OSX and Windows. accdb format, Documents considered suspicious during threat hunting exercises which could not be attributed to UNC1151 used a VBA code that is similar to MacroPack’s commercial VBA scheme which was not used in any of the attack scenarios. Aside from all the junk added by the developer, we can see two important pieces of data when we open the VBA editor: a PowerShell script and a batch script that executes the PowerShell script. The code is working perfectly, apart from the following message being triggered. As we know that how important documents are in a company. vba in all modules, while leaving P-code intact. I'd like to learn how Windows Defender recognizes that piece of VBA script as malicious. However, the tool EvilClippy is fantastic for performing this action and even allows you to replace the uncompiled VBA Streams under the Macros directory are of most signi cance for malicious VBA detection. If the VBA source code is removed, some tools This malicious Word document has been detected as “VBA/Agent. doc | python3 To illustrate how the Office VBA and AMSI integration can expose malicious macro code, let’s look at a recent social engineering attack that uses macro-based malware. Reload to refresh your session. June, July 2020. Additionally, the CallByName function is used to get or set a property, or invoke a method at run time using a string name. Therefore there are limitations on applying pattern-based detection to detecting these unknown malicious Usually, the malicious VBA macros are used to download the second stage of the malware (ransomware, banking Trojan, backdoor, etc. The macro code is a VBA script that extracts the contents of a malicious executable file from an object in the document, drops the executable file on the victim’s machine and finally executes it. 3 Types of Attacks. a. Co-authored by Gustavo Palazolo and Ghanashyam Satpathy Summary. Allows for quick Kurt Natvig wanted to understand whether it’s possible to recompile VBA macros to another language, which could then easily be ‘run’ on any gateway, thus revealing a sample’s true An adversary may hide malicious VBA code by overwriting the VBA source code location with zero’s, benign code, or random bytes while leaving the previously compiled malicious p-code. Anti-virus and analysis tools use heuristics of the VBA source code in an effort to detect such attacks. There are legitimate reasons for doing this, and also malicious ones, I leave the ethics of the uses of these techniques up to the user. 3. Lazy Office Analyzer - Loffice is making use of WinAppDbg to extract URLs' from Office documents but also VB-script and Javascript. In this paper, we summarize the obfuscation techniques and propose an obfuscated macro code detection method using five machine learning classifiers. So, if you have a macro virus, you can activate it just by performing normal everyday tasks, like editing a Word document or opening your emails. Word, Excel), to detect VBA Macros, extract their source code in clear text, and detect security-related patterns such as auto-executable macros, suspicious VBA keywords used by malware, anti-sandboxing and anti-virtualization techniques, and potential IOCs (IP addresses, Malicious VBA- Walkthrough. As long as such a doctored document is not opened with a version of Office that uses a different version of VBA, the malicious p-code will be executed while all source code inspecting tools will be fooled by the benign (or missing) source On March 16, FortiGuard Labs captured a new Word file that spreads malware by executing malicious VBA (Visual Basic for Applications) code. If the VBA source code is removed, some In the evolving landscape of cybersecurity, the prevalence of malicious Visual Basic for Applications (VBA) macros embedded in Office documents presents a formidable challenge. Although malicious VBA code contained with Office documents or templates is a known and well understood attack vector for many years, it still remains current against today's security defences. Vba Purging. We will first look at the samples captured in this campaign and then example of a VBA macro that extracts malicious code from the document’s properties, decodes it, and executes it based on the victim’s operating system. accdb format, Having found the core building blocks for the code, we can now reconstruct the obfuscated instructions and follow the code’s flow. Summary. If the VBA source code is removed, some An adversary may hide malicious VBA code by overwriting the VBA source code location with zero's, benign code, or random bytes while leaving the previously compiled malicious p-code. Document is poisoned with DDE commands, Figure 1 shows its content when it’s opened in Microsoft Word. If the Simple analysis of a malicious document. We then analyzed the sample, and in this blog we are going to explain how it works, step by step. Although efficient, anti-virus and analysis tools are not able to detect macro malware based on VBA opcode (p-code). Save as Excel Macro-Enabled Workbook (. Reverse the URL and “23lldnur”. p df. xml. Other than VBA source code, Bearden et al. The content of this decoy file can be seen in Figure 3 below. Phishing is the best way to send someone a malicious document. NanoCore RAT was developed in the . com Usage: MMG. Request PDF | On Oct 20, 2020, Simon HUNEAULT-LEBLANC and others published P-Code Based Classification to Detect Malicious VBA Macro | Find, read and cite all the research you need on ResearchGate This paper proposes a method to detect unseen malicious macros with the words extracted from the source code, and shows that this method can detect 89% of new malware families. ) I tried hiding the malicious macro (created with Unicorn) by stomping the VBA code with EvilClippy Researcher Kurt Natvig wanted to understand whether it’s possible to recompile VBA macros to another language, which could then easily be ‘run’ on any gateway, thus revealing a sample’s true nature in a safe manner. I have an Excel Workbook, where in some VBA code I try to execute a Powershell Script (self signed, execution policy allsigned, executes fine from the console) Changed recently to Office 365 64bit on a Win10 Pro 1909 - now I get the popup, that a malicious macro has been found. Figure 1 below shows how it looks when it’s opened. Search syntax tips. Three of these included obfuscated payloads designed to download It starts with a malicious email, and ultimately uses Visual Studio Code (VS Code) to distribute Python-based malware that gives attackers unauthorized and persistent remote # Generate call graph directly from an Office file with macros [tnx @doomedraven] python3 vba2graph. Vesselin Bontchev in 2016, this technique allows attackers to remove compressed VBA code from Office documents and still execute malicious macros without many of What can a malicious macro do? Note: It is possible to write malware completely in VBA. Tools that scan for malicious VBA source code may be bypassed as the unwanted code is hidden in the compiled p-code. Net framework, and the latest version is “1. The sample targeted both Apple Mac OS X and Microsoft Windows systems. doc), Excel (. Hence, pattern-based detection has a limitation in detecting these new malicious VBA macros. Due to its inherent functionalities, VBA can be used to automate the execution of malicious codes or even bypass security controls. What does it do? Flips the number signage of all numeric values in the selected cells. A method extracts words from the source code, and constructs a language After all, embedding malicious code into documents, such as Excel spreadsheets or Adobe Acrobat PDF files is quite effective at bypassing perimeter defenses. OLETOOLS • • •A: Automatic triggers •W: Any write operation that may be used to drop a payload •X: Any execute operation • Custom-formatted VBA Code Trips Up Detection. 4. Abstract: VBA macro malware has seen a resurgence of use in recent years by malicious actors as a vector to perpetrate cyber attacks. The detection is performed by extracting n-gram features from p-code sequences, and the classification accuracy is 96. The hard work was done by the AIs, and all • VBA source code • Even encrypted with password VBA String Expressions Deobfuscation (mini VBA Parser) Auto Execution Triggers AutoOpen, Document_Open, Document_Close, ActiveX, Other Detections VBA Stomping XLM / Excel 4 Macros. py tool one more time with the -c or --code option to extract the VBA macro. TALHI, "P-Code Based Classification to Detect Malicious VBA Macro," 2020 International Symposium on Networks, Comput ers and Communications (ISNCC), Montreal, QC, Canada One specific malicious VBA function commonly seen between both sets of maldocs would collect preliminary information and construct a query-based URL to convey the sysinfo to the attackers. Malicious VBA function. Un1k0d3r mr. Ready to dive into the world of malicious VBA code analysis? Let’s tackle this challenge together! 🕵️♂️ Instructions: One of the employees has received a suspicious document attached This form of malware is known for being abusive of the VBA (Visual Basic for Application) programming in Microsoft Office macros to spread other forms of malware. In a new article he explains, step by step, how he recompiled malicious VBA macro code to valid harmless Python 3. Example of a malicious VBA macro payload: The macro runs automatically when the document is opened, extracts and decodes the “Comments” property, writes the content to a temporary file and executes it via However, given the ease of downloading and opening externally created Excel files, one piece of malicious VBA code in one Excel file can bring down an entire company network. 1p. 9 million files (out of which ViperMonkey - ViperMonkey is a VBA Emulation engine written in Python, designed to analyze and deobfuscate malicious VBA Macros. Knowledge itself is not malicious. Added: September 19, 2024 at 8:09 am. Unfortunately it instantly gets detected by major Antivirus companies (McAffee, Malwarebytes, Windows Defender etc. Chapters00:00 Start03:29 Cleaning up the script04:10 Decoding HEX strin Once a victim opens the attached document, a VBA Macro or Excel 4. Close the More Accessing the VBA Environment. The VBA and XLM runtimes report to an antivirus system certain high-risk code behaviors the macro is about to execute. The initial vector is a Word document with instructions Bandook has used malicious VBA code against the target system. During the summer, malware authors started using even better methods. # Generate call graph directly from an Office file with macros [tnx @doomedraven] python2 vba2graph. But, it will not open the VBA code Word file. Typically, threat actors attach a malicious macro inside an Office document that they send alongside phishing emails. (VBA Source code is embedded code in MS Office documents which can be executed on opening the document) - mraptor: used to detect malicious VBA This videos shows a walkthrough of the Malicious-VBA challenge on LetsDefend platform. What is the address of the first cell where Excel 4. Let’s break down the steps taken to analyze the Without knowing the extent of or use cases of this workbook, I can't say just how risky those are but I can say with certainty, nothing is malicious in the code below. The generated Python 3. py -f malicious. My scumbag brother wrote a vba code that runs on opening a spreadsheet, copies the file into the windows startup folder, then shuts down the pc - Causing an endless loop of your pc being shutdown the moment it loads up. Not Detected. Published: 2019-04-23. Because many Social Engineering and Phishing Attacks: Attackers often use social engineering techniques to trick users into enabling macros containing malicious VBA code. internetwar; 09:02 PM 07 Oct 2024; 6. “We created a phishing email, with an attached Excel document that contains malicious VBA code that downloads a reverse shell to the target machine. 1. When the Word file is opened, it shows notifies Performing simple text transformations is often enough to deobfuscate malicious VBA code. The p-code for each VBA line is also stored in the code module stream, before the compressed source code. Introduction. This on its own doesn’t point to anything that I can see, however the exact code is listed on multiple sites with malicious warnings. VBA source code is compiled into P-code, which is stored You signed in with another tab or window. ppam extension which is a PowerPoint file containing VBA code. This study introduces a comprehensive HUNEAULT-LEBLANC and C. The hard work was done by the AIs, and all With increasing quantity and sophistication, malicious code is becoming difficult to discover and analyze. The main attack methods of malicious documents are as follows: embedded VBA malicious code, embedded OLE object, software vulnerabilities, malicious images inserted in Dynamic Data Exchange (DDE), document body, and multimedia files such as flash . If you’d like to know more there are a plethora of online resources on how VBA stomping works. They can be relatively small and are easy to modify or even to completely rewrite them each time, thus making them difficult to detect at the perimeter defenses (e. Published:Thu, 19 Sep 2024 14:32:50 +0000. Tools and Techniques Syntax Highlighting Editors. FLOSS tool to extract hidden Strings. This code is looping to execute a separate Pyomo optimisation for each day. They may use deceptive subject lines, urgent requests, or impersonate trusted entities to entice users to enable macros. Unzipping the documents, and navigate to maldoc-name\word\_rels\document. 2024. Once you click the “Enable Content” button, the malicious VBA Macro is executed covertly in the Request PDF | On Oct 20, 2020, Simon HUNEAULT-LEBLANC and others published P-Code Based Classification to Detect Malicious VBA Macro | Find, read and cite all the research you need on ResearchGate The VBA and XLM runtimes report to an antivirus system certain high-risk code behaviors the macro is about to execute. According to Microsoft, 98 percent of all attacks against Office involve macros. 1109/ACCESS. Listing 1. Today’s challenge revolved around analyzing a Malicious VBA from a suspicious document attached to an Figure 1 shows its content when it’s opened in Microsoft Word. VBA purging is a recent office macro detection evasion technique. VBA code. However, we were able to modify its binary file to remove this restriction. If the VBA source code is removed, some tools An adversary may hide malicious VBA code by overwriting the VBA source code location with zero’s, benign code, or random bytes while leaving the previously compiled malicious p-code. k4j7ech; 08:23 PM 07 Oct 2024; 4. - olevba: used to extract and analyze VBA Macro source code from MS Office documents. bas -o output_folder The code will probably only work if the VBA Editor is open before you run it, because CodeWindow. This will Hey, I am trying to create a malicious Word file that will open a meterpreter shell when executed and macros enabled. They could then embed these macros in Office documents and distribute them online. 22. In addition to providing artifacts from samples, I will regularly post Office macros are very powerful and versatile because they can host VBA code, which is one of the main reasons threat actors use macros. What the VBA code does. Reviewing the extract files, such as OneNoteAttachments folder shows the batch file that contains a malicious payload. In this post, I’ll be walking you through an exciting challenge I tackled on LetsDefend, a platform designed to improve cybersecurity skills through hands-on challenges. Once enabled, the malicious VBA code can execute its intended payload. They sent you the file to investigate. However, there isn’t much Other than VBA source code, Bearden et al. To see all available qualifiers, see Summary. (See the example screenshot below) 13. Muhammad Haroon. The company has released OfficePurge, a new tool that supports VBA purging of Word (. What you want to do, essentially, is write a VBA virus. This guide will help you navigate How did you harden your systems to protect against a malicious Access database? We purchased a code signing certificate so we could use a GPO to only allow signed macros/VBA code to run. - outflanknl/EvilClippy A cross-platform assistant for creating malicious MS Office documents. Identical functions have been seen in Kimsuky maldocs throughout this year. This makes the analysis not impossible but boring and 1- The code first declares a variable “conn” with Dim to create a new instance of ADO object with “ADODB. 30, the BlackBerry Threat Research and Intelligence team explained that the spearphishing attack itself was a weaponized document sent as an email attachment that contained an embedded remote template injection technique and a malicious VBA macro code. Assembled by: The Editor . We will first look at the samples captured in this campaign and then Figure 2 shows the functionalities of VBA used by malicious macros. Regarding the detection of malware in MSOffice documents through machine learning techniques, various approaches have been proposed with respect to feature engineering and classifier choice: 1) VBA macro-based detection, 2) P-code detection, 3) feature engineering through NLP, 4) code Figure 3: Malicious Excel macro Note that the CLng function is an Excel a built-in function that converts a value to a long integer and can be used as a VBA function (VBA) in macro code. 3. But in practice, VBA macros are mostly used to write Droppers or Downloaders, to trigger other To illustrate how the Office VBA and AMSI integration can expose malicious macro code, let’s look at a recent social engineering attack that uses macro-based malware. To detect new malicious VBA macros, some methods with machine learning techniques have been proposed. This allows the antivirus system to indicate whether or not the macro behavior is malicious. Also note that this code will also close the Project Explorer, Immediate Window, Property Window etc in the VBE. Connection” that opens connection to the database. The main routine lies in a function named “eFile”, which is executed by the “AutoOpen” functionality. When victims open the lure document, Office displays a security warning saying that macros This paper discusses the extraction of p-code within macro based documents and presents the classification of benign and malicious p- code using five learning classifiers and obtained a high accuracy (98. Generates a VBA call graph, with potential malicious keywords highlighted. VBA and Cybersecurity. In targeted email attacks, malicious Static analysis is the process of analysing malicious code, whether it be a script or a program, to determine what action the code is trying to execute. If the behavior is determined to be malicious, the Office application closes the session and the antivirus system can quarantine the This paper discusses the extraction of p-code within macro based documents and presents the classification of benign and malicious p- code using five learning classifiers and obtained a high accuracy (98. Our method extracts words from the source code and converts into feature vectors with some Natural Language Processing techniques. The crooks from Epic Malicious code, also known as malware, is a type of software that attacks an application or system. 3 Machine Learning Techniques for Detecting Malicious VBA Code. The sentiment used was finance-related themes such as: “ New PO300093 Order ” as shown in Figure 2. You managed to extract some strings from the VBA Macro document. doc -c 2 # Generate vba code using olevba then pipe it to vba2graph olevba3 malicious. rels will reveal the HTML URL which will However, to detect malicious MS office documents most researchers have devoted their efforts to using natural language processing methods to extract several features of the VBA code, both in terms I am building an energy system model that is using a combination of VBA and Python (Pyomo). (Joshua Feldman et al. Auto_Open runs when this A tool for security researchers, who waste their time analyzing malicious Office macros. In fact, In this post, I’ll be talking about other techniques I’ve learned, including calling Windows API functions, and I’ll be discussing my (somewhat) failed attempt to write VBA that dumps the Macro code is embedded in Office documents written in a programming language known as Visual Basic for Applications (VBA). 14. In this blog, we will focus on what these malicious documents look like and how they drop Emotet malware onto a victim's local disk. I've read that it uses both signature-based scanning along with runtime execution analysis. Hot Take: **_Looks like Rockwell Automation just got a An adversary may hide malicious VBA code by overwriting the VBA source code location with zero’s, benign code, or random bytes while leaving the previously compiled malicious p-code. Zoom = True 'Select first cell on worksheet Range("A1"). When a user opens such a file, the macro runs automatically, executing negative actions like spreading malware, stealing data, or Co-authored by Gustavo Palazolo and Ghanashyam Satpathy. The Lets Defend: Malicious VBA Challenge Writeup. google. With this potentially suspicious bit missing and being used as a marker by antimalware tools, the files turned out to have surprisingly high evasion rates. 0 macros work to provide the same functionality? auto_open. Stomp VBA (abuse P-code) Put fake VBA code from text file fakecode. Step 4: Analyze an Obfuscated Script. Our last sample is another Word variant, and I definitely save An adversary may hide malicious VBA code by overwriting the VBA source code location with zero’s, benign code, or random bytes while leaving the previously compiled malicious p-code. Thus, attacks using macro-based malicious documents are still very common and can do a huge amount of damage considering the popularity of Microsoft Office apps. doc -c 2 # Generate vba code using olevba then pipe it to vba2graph olevba malicious. S1039 : Bumblebee : Bumblebee can create a Visual Basic script to enable persistence. The source code in this stream is compressed using the MS-OVBA algorithm [16] and there Learn how to extract VBA code from a malicious Microsoft Office document. Blue Request PDF | Using LSI to Detect Unknown Malicious VBA Macros | Targeted email attacks are one of the main threats to organizations of all sizes and fields. This begins the sequence of events that leads to the infection of the computer. dldr” by the FortiGuard AntiVirus service. This Strings can determine if the file is malware or not such as functions, Originally identified by Dr. A sample shared by nao_sec that abusing ms-msdt to execute code. Others support dynamic analysis with the aim of extracting the run-time IOCs. Sign in to view more content Create your free account or sign in to continue your search Stomp VBA (abuse P-code) Put fake VBA code from text file fakecode. 3]. Query. We have also seen many techniques employed by attackers when it comes to infected documents, such as the usage of PowerShell and WMI to spilled in the shark-rich waters, attract malicious actors who try to abuse this feature of productivity apps to subsequently deliver a malicious payload. This note deals with one such scenario, focusing on how to extract Visual Basic (VB) macro code that may be embedded in malicious Microsoft Office files. Document contains suspicious module names. 8%) and is promising for macro malware detection in real-world applications. Upon considering the reason for the array of malicious documents, a distinct recurrent phenomenon was noticed. Therefore there are limitations on applying pattern-based detection to detecting these unknown malicious These malicious VBA macros are obfuscated in several ways to deceive anti-virus programs. Maybe you can’t open the VBA Password Protect Word file because you have forgotten the password or are typing the wrong password in the VBA Macro file. 3% on 158 The aim, according to one of the researchers, was to break obfuscation-related signatures that anticipate CHAR. Dde String. , with an e-mail scanner) with known-malware detection tools. So far, My goal is to recompile malicious VBA macro code to valid harmless Python 3. 0”. Macro malware is a strain of malware found in VBA macros in Microsoft Office files. This study introduces a comprehensive Abstract: VBA macro malware has seen a resurgence of use in recent years by malicious actors as a vector to perpetrate cyber attacks. io If you’d like to know more there are a plethora of online resources on how VBA stomping works. Another tool that we can use to easily see the contents of the macros embeded in the document would be using olevba, which will attempt to extract the contents of the file. Include my email address so I can be contacted . Find and fix vulnerabilities Actions. In this blog post we will explore the features of Evil Clippy and the Enhancing Cybersecurity With P-Code Analysis and XGBoost: A Novel Approach for Malicious VBA Macro Detection in Office Documents Ahmadi, Candra; Chen, Jiann-Liang; Lai, Yi-Cheng; Abstract . We will first look at the samples captured in this campaign and then Usually, the malicious VBA macros are used to download the second stage of the malware (ransomware, banking Trojan, backdoor, etc. The link provided in the popup (tells me, that documents that are stored in a trusted Once a victim opens the attached document, a VBA Macro or Excel 4. epfo canrk ydhwkj gckokvp aoai dav idgiue nbczqf nstxpch pgcwvof