Over the years, the set of skills needed to analyze malware has been expanding. After all, software is becoming more sophisticated and powerful, regardless whether it is being used for benign or malicious purposes. The expertise needed to understand malicious programs has been growing in complexity to keep up with the threats.
My perspective on this progression is based on the reverse-engineering malware course I’ve been teaching at SANS Institute. Allow me to indulge in a brief retrospective on this course, which I launched over a decade ago and which was recently expanded.
Starting to Teach Malware Analysis
My first presentation on the topic of malware analysis was at the SANSFIRE conference in 2001 in Washington, DC, I think. That was one of my first professional speaking gigs. SANS was willing to give me a shot, thanks to Stephen Northcutt, but I wasn’t yet a part of the faculty. My 2.5-hour session promised to:
Discuss “tools and techniques useful for understanding inner workings of malware such as viruses, worms, and trojans. We describe an approach to setting up inexpensive and flexible lab environment using virtual workstation software such as VMWare, and demonstrate the process of reverse engineering a trojan using a range of system monitoring tools in conjunction with a disassembler and a debugger.”
I had 96 slides. Malware analysis knowledge wasn’t yet prevalent in the general community outside of antivirus companies, which were keeping their expertise close to the chest. Fortunately, there was only so much one needed to know to analyze mainstream samples of the day.
Worried that evening session attendees would have a hard time staying alert after a day’s full of classes, I handed out chocolate-covered coffee beans, which I got from McNulty’s shop in New York.
Expanding the Reverse-Engineering Course
A year later, I expanded the course to two evening sessions. It included 198 slides and hands-on labs. I was on the SANS faculty list! Slava Frid, who helped me with disassembly, was the TA. My lab included Windows NT and 2000 virtual machines. Some students had Windows 98 and ME. SoftICE was my favorite debugger. My concluding slide said:
That advice applies today, though one of the wonderful changes in the community from those days is a much larger set of forums and blogs focused on malware analysis techniques.
By 2004, the course was two-days long and covered additional reversing approaches and browser malware. In 2008 it expanded to four days, with Mike Murr contributing materials that dove into code-level analysis of compiled executables. Pedro Bueno, Jim Shewmaker and Bojan Zdrnja shared their insights on packers and obfuscators.
In 2010, the course expanded to 5 days, incorporating contributions by Jim Clausing and Bojan Zdrnja. The new materials covered malicious document analysis and memory forensics. I released the first version of REMnux, a Linux distro for assisting malware analysts with reverse-engineering malicious software.
Recent Course Expansion: Malware Analysis Tournament
The most recent development related to the course is the expansion from five to six days. Thanks to the efforts of Jake Williams, the students are now able to reinforce what they’ve learned and fine-tune their skills by spending a day solving practical capture-the-flag challenges. The challenges are built using the NetWars tournament platform. It’s a fun game. For more about this expansion, see Jake’s blog and tune into his recorded webcast for a sneak peek at the challenges.
It’s exciting to see the community of malware analysts increase as the corpus of our knowledge on this topic continues to expand. Thanks to all the individuals who have helped me grow as a part of this field and to everyone who takes the time to share their expertise with the community. There’s always more for us to learn, so keep at it.
There is much we can learn about coordinated online activities of skilled attackers with nation-state affiliations. The following two write-ups provide a wealth of information about one such attack group, which has been targeting organization in South Asia over the past few years and appears to reside in India:
According to these reports, the group engaged in industrial espionage and spying on political activists. The victims resided in many countries, but Pakistan stood out as the most targeted location. The attackers relied on spear phishing to gain initial access to the targeted environment. The emails were thematically appropriate to the targets and included malicious documents that exploited unpatched vulnerabilities. Some of the malware was digitally signed.
The analysts attributed these cyberattack activities to specific source by examining:
As the result, Norman and Shadowserver researchers concluded that the attackers apparently operated from India “and have been conducting attacks against business, government and political organizations.” Similarly, ESET analysts concluded “that the entire campaign originates from India.”
In addition, Norman and Shadowserver researchers concluded that the malicious software used in these campaigns was created by multiple software developers who were “tasked with specific malware deliverances.” The developers collaborated, “working on separate subprojects, but apparently not using a centralized source control system.”
In the past weeks I published several posts describing malware analysis tools and approaches at other blogs:
Also, on my own blog I took a look at Cylance’s Accelerify tool for speeding up the lab system’s clock for malware analysis.
Some organizations have encountered Advanced Persistent Threat over 5 years ago—earlier than most of us. Because of the types of data they process, these initial APT victims were exposed to carefully-orchestrated, espionage-motivated attacks before they spread to a wider range of targets.
Now, half a decade later, might the time to look at the attacks that the initial APT victims are fighting nowadays to forecast the threats that will eventually reach other companies. I am wondering:
It’s hard to answer these questions without first-hand access to the companies that witnessed the first wave of APT attacks. Furthermore, the dilution of the term APT by marketing departments makes it harder to differentiate between reliable APT insights, such as what Mandiant has been publishing, from generic APT-themed sales collateral peppered throughout the web.
Based on public information and observations, I suspect the threat landscape over the next few years will involve:
These are just conjectures. I don’t have the answers to the questions I posed above; however, I thought I’d at least ask them and explore the idea of looking at early APT targets’ current state to anticipate advanced threats that will later affect other organizations.
Related articles you might like:
In the field of IT in general and digital forensics in particular, you become obsolete the moment you stop learning. Here are several free recorded webcasts related to reverse-engineering and malware analysis that will help you keep your skills up to date:
The need to define custom, incident-specific signatures is slowly gaining traction in the mainstream enterprise. A few years ago this concept, often called Indicators of Compromise (IOCs), was mostly discussed by government organizations and defense contractors who were coming to terms with Advanced Persistent Threat (APT) attacks.
Madiant began popularizing the term IOC around 2007. Kris Kendall’s paper Practical Malware Analysis mentioned IOCs in the context of malware reversing at Black Hat DC 2007. For a precursor to this, see Kevin Mandia’s Foreign Attacks on Corporate America slides from Black Hat Federal 2006. At the time, few organizations saw the need to go beyond antivirus-based detection by analyzing the adversary’s artifacts to define custom host-level signatures.
Now, several years later, the term IOC is pretty well-known in the infosec industry. More companies are adding malware and related analysis skills to incident response teams. As Jake Williams put it, such firms know how to examine new malware and extract IOCs. “These are then fed back into the system and scans are repeated until no new malware is found.” Automated analysis products from vendors such as Norman, Mandiant, FireEye and HB Gary are being increasingly positioned as IR triage-enablers.
That said, the knowledge and skills for deriving and using IOCs is far from being mainstream. Anton Chuvakin highlighted the distinction between security haves and have-nots along the lines of this capability. The haves know how to reverse-engineer malware to “extract the IOCs FAST (or get those IOCs shared with you by trusted friends) and then look for them on other systems.”
IOC techniques haven’t entered the mainstream just yet. But we’re heading in that direction, as more people attain forensics skills and as more tools become available for defining and making use of such custom, incident-specific signatures.
To learn how to define and make use of IOCs, take a look at:
Think you know malware? I created a new fun quiz to see whether you can recognize the 10 malware specimens you should probably know by name. Test your knowledge and learn something along the way.
If you like this approach to learning, here are two more quizzes I put together:
— Lenny Zeltser
I had the pleasure of speaking with Jake Williams, my colleague at SANS Institute, about his perspective on various malware analysis and reverse-engineering topics. You can read the interview in three parts:
Jake is highly experienced in this space and shared helpful insights in the interview above. Jake will be teaching FOR610: Reverse-Engineering Malware on several occasions at SANS this year.
Be doubly vigilant after a physical break-in. Don’t just look for what’s missing, but what might have been left behind.