Looking for Processes with Redline

The Mandiant Redline application is another option for analyzing the memory image file. To use Redline, copy the Windows memory images off the Examiner system to a separate Windows workstation, where the Mandiant Redline application is installed.

Mandiant Redline (Figure 11) is a free tool that provides host investigative capabilities to users and uncovers signs of malicious activity through memory and file analysis to develop a threat assessment profile. After I infected the test Windows box with a known malware variant and allowed the system to react, the machine wanted to restart at that moment. I acquired a memory image and loaded it into Redline. I then allowed the machine to reboot and took another memory image. All the processes that are running on the system are in Figure 12 (left, before reboot, and right, after reboot).

Figure 11: Loading a memory image for Mandiant Redline. Choose I am Reviewing a Full Live Response or Memory Image.

Figure 12: Redline shows the total number of processes running after installing malware (left), then a list of processes running after reboot (right).

After comparing the two different lists, I see that, after reboot, new processes are running (jh MRI Score 61 PID 38533 and svchost.exe MRI Score 61 PID 1560). MRI (Malware Risk Index) is a score Redline uses to assess the likelihood that a process or artifact is associated with a malware event. Redline calculates the Malware Risk Index (MRI) score, which you can use to prioritize your investigation. The higher the MRI score, the more likely Redline has identified a potential compromise. You should inspect each process that is "redlined" (i.e., given a high MRI score) to determine the reasons Redline scored it as a threat. In this case, Redline didn't label the threat very high, but it is interesting that it is the highest scoring process, and it wasn't running before the malware was executed on the box. This process needs further investigation.

Conclusion

Every malware attack is different, and every investigation must follow a path based on the evidence, but that doesn't mean you can't bring your incidence response team together in advance and assemble the necessary tools, so you'll be ready in a crisis. In this article, I described some tools investigators use for obtaining and analyzing the memory of an infected system. In a later article, I will take a closer look at memory analysis tools such as Volatility and Mandiant Redline.