DFIR Tools, Ransomware Thoughts

I like to keep up on new tools that are discussed in the community, because they offer insight into what other analysts are seeing.  The DFIR community at large isn’t really that big on sharing what they’ve seen or done, and seeing tools being discussed is something of a "peek behind the curtain", as it were.

SRUM
A recent ISC handler diary entry described a tool for parsing System Resource Utilization Monitor (SRUM) data.

As soon as I read the diary entry, I went back through some of my recent cases, but wasn’t able to find any systems with resource monitoring enabled.

SCCM
The folks at FireEye released a tool for parsing process execution information from the WMI repository.

I still strongly recommend that some form of process creation monitoring be installed or enabled on endpoints, whether its Sysmon, or something else.

Ransomware
Something else I’ve been interested in for quite some time is ransomware.  As an incident responder, I’m most often in contact with organizations that have suffered breaches, and these organizations vary greatly with respect to the maturity of their infosec programs.  However, the whole issue of ransomware is not just an annoyance that is part of the price of being part of a connected, e-commerce world.  In fact, ransomware is the implementation of a business model that monetizes what many organizations view as "low-value targets"; because it’s a business model, we can expect to see developments and modifications/tweaks to that model to improve it’s efficacy over the next year.

Last year, SecureWorks published a couple of posts regarding the Samas ransomware.  One of them illustrates the adversary’s life cycle observed across multiple engagements; the other (authored by Kevin Strickland, of the IR team) specifically addresses the evolution of the Samas ransomware binary itself.

The folks at CrowdStrike published a blog post on the topic of ransomware, one that specifically discusses ransomware evolving over time.  A couple of thoughts regarding the post:

First, while there will be an evolution of tactics, some of the current techniques to infect an infrastructure will continue to be used.  Why?  Because they work.  The simple fact is that users will continue to click on things.  Anyone who monitors process creation events sees this on a weekly (daily?) basis, and this will continue to cost organizations money, in lost productivity as the IT staff attempt to recover.

Second, there’s the statement, "Samas: This variant targets servers…"; simply put, no, it doesn’t.  The Samas ransomware is just ransomware; it encrypts files.  As with Le Chiffre and several other variants of ransomware, there are actual people behind the deployment of the Samas ransomware.  The Samas ransomware has no capability whatsoever to target servers.  The vulnerable systems are targeted by an actual person.

Finally, I do agree with the authors of the post that a new approach is needed; actually, rather than a "new" approach, I’d recommend that organizations implement those basic measures that infosec folks have been talking about for 20+ years.  Make and verify backups, keep those backups off of the network.  Provide user awareness training, and hold folks responsible for that training.  Third-parties such as PhishMe will provide you with statistics, and identify those users who continue to click on suspicious attachments.

With respect to ransomware itself, is enough effort being put forth by organizations to develop and track threat intelligence?  CrowdStrike’s blog post discusses an evolution of "TTPs", but what are those TTPs?  Ransomware is a threat that imposes significant costs on (and subsequently, a significant threat to) organizations by monetizing wide swathes of un-/under-protected systems.

Source: Windows Incident Response @ January 31, 2017 at 04:00PM

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