Login
McAfee Labs have been observing a spike in phishing campaigns that utilize Microsoft office macro capabilities. These malicious documents reach victims via mass spam E-mail campaigns and generally invoke urgency, fear, or similar emotions, leading unsuspecting users to promptly open them. The purpose of these spam operations is to deliver malicious payloads to as many people as possible.
A recent spam campaign was using malicious word document to download and execute the Ursnif trojan. Ursnif is a high-risk trojan designed to record various sensitive information. It typically archives this sensitive data and sends it back to a command-and-control server.
This blog describes how attackers use document properties and a few other techniques to download and execute the Ursnif trojan.
Threat Summary
Infection Chain
The malware arrives through a phishing email containing a Microsoft Word document as an attachment. When the document is opened and macros are enabled, Word downloads a DLL (Ursnif payload). The Ursnif payload is then executed using rundll32.exe
Figure-1: flowchart of infection chain
Word Analysis
Macros are disabled by default and the malware authors are aware of this and hence present an image to entice the victims into enabling them.
Figure-2: Image of what the user sees upon opening the document
VBA Macro Analysis of Word Document
Analyzing the sample statically with ‘oleId’ and ‘olevba’ indicates the suspicious vectors..
Figure-3: Oleid output
Figure-4: Olevba output
The VBA Macro is compatible with x32 and x64 architectures and is highly obfuscated as seen in Figure-5
Figure-5: Obfuscated VBA macro
To get a better understanding of the functionality, we have de-obfuscated the contents in the 2 figures shown below.
Figure-6: De-obfuscated VBA macro (stage 1)
Figure-7: De-obfuscated VBA macro (stage 2)
An interesting characteristic of this sample is that some of the strings like CLSID, URL for downloading Ursnif, and environment variables names are stored in custom document properties in reverse. As shown in Figure-7, VBA function “ActiveDocument.CustomDocumentProperties()” is used to retrieve the properties and uses “StrReverse” to reverse the contents.
We can see the document properties in Figure-8
Figure-8: Document properties
Payload Download and Execution:
The malicious macro retrieves hidden shellcode from a custom property named “Company” using the “cdec” function that converts the shellcode from string to decimal/hex value and executes it. The shellcode is shown below.
Figure-9: Raw Company property
The shellcode is written to memory and the access protection is changed to PAGE_EXECUTE_READWRITE.
Figure-10: Code of VirtualProtect
Figure-11: Shellcode’s memory and protection after calling VirtualProtect()
After adding the shellcode in memory, the environment variable containing the malicious URL of Ursnif payload is created. This Environment variable will be later used by the shellcode.
Figure-12: Environment variable set in Winword.exe space
The shellcode is executed with the use of the SetTimer API. SetTimer creates a timer with the specified time-out value mentioned and notifies a function when the time is elapsed. The 4th parameter used to call SetTimer is the pointer to the shellcode in memory which will be invoked when the mentioned time is elapsed.
Figure-13: SetTimer function (Execution of shellCode)
The shellcode downloads the file from the URL stored in the environmental variable and stores it as ” y9C4A.tmp.dll ” and executes it with rundll32.exe.
| URL | hxxp://docmasterpassb.top/kdv/x7t1QUUADWPEIQyxM6DT3vtrornV4uJcP4GvD9vM/ |
| CMD | rundll32 “C:\Users\user\AppData\Local\Temp\y9C4A.tmp.dll”,DllRegisterServer |
Figure-14: Exports of Downloaded DLL
After successful execution of the shellcode, the environment variable is removed.
Figure-15: Removal of Environment Variable
IOC
| TYPE | VALUE | PRODUCT | DETECTION NAME |
| Main Word Document | 6cf97570d317b42ef8bfd4ee4df21d217d5f27b73ff236049d70c37c5337909f | McAfee LiveSafe and Total Protection | X97M/Downloader.CJG |
| Downloaded dll | 41ae907a2bb73794bb2cff40b429e62305847a3e1a95f188b596f1cf925c4547 | McAfee LiveSafe and Total Protection | Ursnif-FULJ |
| URL to download dll | hxxp://docmasterpassb.top/kdv/x7t1QUUADWPEIQyxM6DT3vtrornV4uJcP4GvD9vM/ | WebAdvisor | Blocked |
MITRE Attack Framework
| Technique ID | Tactic | Technique Details | Description |
| T1566.001 | Initial Access | Spear phishing Attachment | Manual execution by user |
| T1059.005 | Execution | Visual Basic | Malicious VBA macros |
| T1218.011 | Defense Evasion | Signed binary abuse | Rundll32.exe is used |
| T1027 | Defense Evasion | Obfuscation techniques | VBA and powershell base64 executions |
| T1086 | Execution | Powershell execution | PowerShell command abuse |
Conclusion
Macros are disabled by default in Microsoft Office applications, we suggest keeping it that way unless the document is received from a trusted source. The infection chain discussed in the blog is not limited to Word or Excel. Further threats may use other live-off-the-land tools to download its payloads.
McAfee customers are protected against the malicious files and sites detailed in this blog with McAfee LiveSafe/Total Protection and McAfee Web Advisor.
The post Test Post appeared first on McAfee Blog.
It’s easy to imagine where we would be without women in technology.
We’d be poorer for it.
With Mother’s Day upon us, I couldn’t help but think once more about the stark employment figures I shared in my International Women’s Day blog just a few weeks ago. Millions of women have involuntarily left the workforce at a much higher rate than men during the pandemic—with roughly one third of women in the U.S. aged 25-44 citing that childcare was the reason for that unemployment.
Reflecting on this further, I thought about the women in technology who’ve left their positions during this past year. It’s a loss of talent and capability that’s set back decades of advances by trailblazing women who not only shine in their field yet also do so in male-dominated realms of study, research, and employment.
So as we look ahead to recovery, we should also look back. By celebrating just a few of the women in technology who shaped our world today, women who truly are “mothers of invention,” perhaps we can remember just how vital women are in our field—and how we should double down on our efforts to welcome them back.
Imagine a time when the term “software engineering” wasn’t recognized, even though it was crucial to us landing on the moon.
Such were the days when Margaret Hamilton began her work at Massachusetts Institute of Technology (MIT) as a job to support her family while her husband went to law school at Harvard. This was in 1959 and would introduce her to Edward Lorenz, the father of chaos theory, and put her on the path to help humanity set its first footsteps on the moon.
It was her work and her code that developed a software-driven system that warned astronauts of in-flight emergencies, an advance she credits her young daughter for inspiring, as recounted in this interview:
Often in the evening or at weekends I would bring my young daughter, Lauren, into work with me. One day, she was with me when I was doing a simulation of a mission to the moon. She liked to imitate me – playing astronaut. She started hitting keys and all of a sudden, the simulation started. Then she pressed other keys and the simulation crashed … I thought: my God – this could inadvertently happen in a real mission.
I suggested a program change to prevent a prelaunch program being selected during flight. But the higher-ups at MIT and NASA said the astronauts were too well trained to make such a mistake. Midcourse on the very next mission, Apollo 8, one of the astronauts on board accidentally did exactly what Lauren had done. The Lauren bug! It created much havoc and required the mission to be reconfigured. After that, they let me put the program change in, all right.
When you search online, you have this woman to thank.
A true pioneer, Karen Spärck Jones worked at Cambridge, during which time she developed the algorithm for deriving a statistic known as “term frequency–inverse document frequency” (TFIDF). In lay terms, TFIDF determines how important a word is relative to the document or collection of terms in which it is found. Sound familiar? It should, as her work forms the basis of practically every search engine today.
Spärck Jones remained outspoken with regards to what she referred to as “professionalism” in technology. This had two layers: the first being the technical efficacy of a solution, the second being the rationale for even doing it in the first place. In her words,
“[T]o be a proper professional you need to think about the context and motivation and justifications of what you’re doing … You don’t need a fundamental philosophical discussion every time you put finger to keyboard, but as computing is spreading so far into people’s lives you need to think about these things.”
Her vision for computing and her hands-on work led to development of COBOL, a programming language still in use today. Driving that vision was the belief that human language could be used as the basis for a programming language, making it more accessible, particularly for business use. The result was the FLOW-MATIC programming language, which was later developed into COBOL, a language that is estimated to be used in 95% of ATM card swipes.
During her time as a naval officer, she helped transform centralized Defense Department systems into smaller, distributed networks akin to the internet we now know and use. At her retirement near the age of 80, she went to work in the private sector where she held the role of full-time senior consultant until her passing at age 85. This 1983 profile of her, aired when she was 76, is certainly worth a watch.
Quite plainly, Perlman’s work paved the way for the routing protocols that underpin the modern internet.
Prior to Perlman’s work, as networks grew and accordingly became more complex, data would often flow into loops that prevented them from reaching their intended destination. Enter her creation of the Spanning Tree Protocol (STP), which can handle large clouds of computers and network devices. While its since evolved, the concept of an adaptive network remains squarely in place.
Another advance of hers was introducing computer programming to young children aged 3 to 5 back in the 1970s. While working at MIT’s LOGO Lab, she created TORTIS (Toddler’s Own Recursive Turtle Interpreter System), which used buttons from programming and allowed for experimentation with a robotic turtle that would follow a toddler’s commands. In the abstract for her paper that documented the work, she emphasized what she felt was a vital point, “Most important of all, it should teach that learning is fun.”
These women have led and inspired, and likewise it’s on all of us in technology to build on the advances they made possible through both our work and the workplace cultures we foster—particularly as we begin our recovery from this pandemic.
One of the many reasons I’m proud to be a part of McAfee is our Women in Security (WISE) community. It’s truly a forward-thinking program, which we introduced to enrich and support women in the tech sector through mentorship programs and professional development conferences. It’s one of the several, tangible ways we actively strive for a vibrant and diverse culture at McAfee.
Another powerful voice for women in tech is AnitaB.org, which supports women in technical fields, as well as the organizations that employ them and the academic institutions training the next generation. A full roster of programs help women grow, learn, and develop their highest potential.
And for looking forward yet further, there’s Girls Who Code, which is building the next generation of female engineers and technologists. Their data shows why this is so vital. They found that 66 percent of girls aged six to 12 show interest in computing, but that drops to 32 percent for girls aged 13 to 17, and then plummets to only 4 percent for college freshmen. Accordingly, they support several programs for school-aged girls from third grade up through senior year of high school, help educators and communities launch clubs, and advocate for women in their field through their work in public policy and research.
And that’s just for starters. For an overview of yet more organizations where you can get involved, check out this list of 16 organizations for women in tech—all of which help us realize a better world with women in technology.
The post The Mothers of Invention: Women Who Blazed the Trail in Technology appeared first on McAfee Blogs.
FreshRSS 