Adversaries don’t work 9-5 and neither do we. At eSentire, our 24/7 SOCs are staffed with Elite Threat Hunters and Cyber Analysts who hunt, investigate, contain and respond to threats within minutes.
We have discovered some of the most dangerous threats and nation state attacks in our space – including the Kaseya MSP breach and the more_eggs malware.
Our Security Operations Centers are supported with Threat Intelligence, Tactical Threat Response and Advanced Threat Analytics driven by our Threat Response Unit – the TRU team.
In TRU Positives, eSentire’s Threat Response Unit (TRU) provides a summary of a recent threat investigation. We outline how we responded to the confirmed threat and what recommendations we have going forward.
Here’s the latest from our TRU Team…
What did we find?
In June 2024, eSentire’s Threat Response Unit (TRU) observed an intriguing case involving a Vidar Stealer infection initiated through a fake IT support website (Figure 1). The infection began when the victim performed a web search for solutions to a Windows Update Error code.
During their search they visited PCHelper Wizards, an IT Support themed site, which provided instructions to resolve the issue using an obfuscated PowerShell script. This script eventually led to a Vidar Stealer infection using the updated Hijack Loader (IDAT Loader) variant that uses netsh.exe for process injection.
PCHelper Wizards, shown above, contains an article with a convenient solution to the error code sought out by the victim. The article even provides the instructions to run PowerShell as Administrator (Figure 2).
The user can copy the code from the website or download and execute it (Figure 3).
The script decodes the first Base64 string to hxxps://ghufal.answermedia[.]site/KB/KB66958646. The “Invoke-WebRequest” command uses this URL to download a ZIP archive and save it to a randomly generated directory within the %TEMP% folder.
After successfully downloading and verifying the presence of the file, the script decodes the second Base64 string to hxxps://ghufal.answermedia[.]site/KB/post.php?status=2. The script uses the URL to make a POST request, likely reporting back to the C2 that the download stage has been completed successfully.
If the script successfully executes the executable files found within the unzipped payload, it decodes the third Base64 string to another URL hxxps://ghufal.answermedia[.]site/KB/post.php?status=3.
It then sends a POST request to the URL to notify that the payload has been executed, marking the successful completion of the infection (Figure 4).
During our investigation, we discovered a related YouTube video containing comments from bots falsely claiming the solution was effective and boasting the validity of the solution.
The video includes the link to a malicious website and describes the steps required to execute the malicious PowerShell code (see Figure 5).
This case study highlights a concerning threat in which threat actors exploit common IT issues to deploy malware. The attackers cleverly created a scenario where users are lured to a fake IT support site offering a malicious PowerShell script to solve a Windows Update Error.
What did we do?
Our team of 24/7 SOC Cyber Analysts isolated the affected host and notified the customer of suspicious activities.
What can you learn from this TRU Positive?
- The use of PowerShell, a legitimate and powerful tool in Windows environments, underscores the importance of monitoring and controlling administrative tools within an organization to prevent misuse by attackers.
- The attackers exploited common user problems, such as Windows Update errors, to lure users to a fake IT support website. This highlights the effectiveness of social engineering tactics and the need for users to be cautious about the authenticity of the solutions they find online.
- The involvement of a YouTube video with bot-generated likes and comments promoting the malicious site demonstrates the extent to which attackers integrate multiple platforms to create a convincing scam environment.
- This case serves as a reminder of the need for continuous cybersecurity education for all users to recognize potential threats and avoid engaging with suspicious links and instructions.
Recommendations from our Threat Response Unit (TRU):
We recommend implementing the following controls to help secure your organization:
Indicators of Compromise
You can access Indicators of Compromise here.
References
Source: Original Post