Attacks/Breaches

12/13/2017
08:20 PM
Connect Directly
Google+
Twitter
RSS
E-Mail
50%
50%

Malware Decompiler Tool Goes Open Source

Avast's RetDec machine-code decompiler now available for free on Github.

Anti-malware vendor Avast has donated its homegrown malware decompiler tool to the open-source community.

Avast's RetDec basically converts a piece of malware into a higher-level programming language and helps malware analysts unmask the inner workings and functions of its code. "It turns it into something that looks like the original source code," says Jakub Kroustek, threat lab team lead at Avast. "It's much easier" and more efficient to sleuth just what the malware can do when it's decompiled, he notes.

"We're facing millions of new samples of malware each day. We're not deeply analyzing all of them, but by using decompilation we can handle some" more closely and quickly, says Kroustek, founder of the tool.

Researchers at Avast used the tool to decompile ransomware strains including Apocalypse, BadBlock, Bart, CrySIS, and TeslaCrypt, and then offer free decryption tools for the ransomware.

Decompiler tools provide static analysis of code, where researchers don't actually run the code but instead study it, up close. Dynamic analysis is another method, where a researcher executes malicious code in the safety of a sandbox environment to study how it runs in action. "Sometimes it's right to use a sandbox, and other times it's beneficial to use a decompiler," he says. "In my case, I usually use both. When you're fighting bad guys, you trying using every leverage" you can, he says.

RetDec was first created in 2011 by researchers at the Czech Republic's Brno University of Technology and AVG Technologies, and the tool became Avast's last year after it acquired AVG. Kroustek says Avast hopes to get other security experts to help further its development as an open source tool, which is aimed at researchers and reverse-engineers.  

Decompilation tools are nothing new. There are commercial products, which can be pricey and limited in customization, Kroustek says, while there are other open-source decompiler tools such as DCC, Boomerang, and Snowman, for example.

"While good decompilation tools are available that deliver good results, many are paid products, however, these cannot be easily extended with custom features," he says. "On the other hand, users can utilize existing, free, open-source decompilers, but these do not always achieve proper stability, code readability and quality."

John Bambanek, threat systems manager with Fidelis Cybersecurity, who also teaches at the University of Illinois at Urbana-Champaign, says an open-source decompiler such as Avast's can be especially helpful for academia. "I have limited funds and buying a bunch of IDA [Hex-Rays decompiler product] seats isn't going to happen. With something open-source, assuming it can get the job done, [the tool can] "provide a great resource for me to produce more reverse engineers," he says.

Avast says the now open-source tool works on multiple architectures, file formats, and operating systems, and can be used for more than decompilation, too. It uses C and Python-type language for output, and runs on Linux and Windows platforms. RetDec source code and related tools are available now on GitHub, under an MIT license.

"If someone isn't focused on decompilers, he or she can just use the libraries for detection of particular patterns" in the malware, for example, Kroustek says.

Related Content:

Kelly Jackson Higgins is Executive Editor at DarkReading.com. She is an award-winning veteran technology and business journalist with more than two decades of experience in reporting and editing for various publications, including Network Computing, Secure Enterprise ... View Full Bio

Comment  | 
Print  | 
More Insights
Comments
Newest First  |  Oldest First  |  Threaded View
REISEN1955
50%
50%
REISEN1955,
User Rank: Ninja
12/15/2017 | 8:29:48 AM
Shareware
Had to laugh at this --- when malware scripting tools show up as shareware (anybody here remember a wonderful catalog PUBLIC BRAND SOFTWARE ) then we are ALL in trouble. 
12 Free, Ready-to-Use Security Tools
Steve Zurier, Freelance Writer,  10/12/2018
Most IT Security Pros Want to Change Jobs
Dark Reading Staff 10/12/2018
6 Security Trends for 2018/2019
Curtis Franklin Jr., Senior Editor at Dark Reading,  10/15/2018
Register for Dark Reading Newsletters
White Papers
Video
Cartoon Contest
Current Issue
Flash Poll
The Risk Management Struggle
The Risk Management Struggle
The majority of organizations are struggling to implement a risk-based approach to security even though risk reduction has become the primary metric for measuring the effectiveness of enterprise security strategies. Read the report and get more details today!
Twitter Feed
Dark Reading - Bug Report
Bug Report
Enterprise Vulnerabilities
From DHS/US-CERT's National Vulnerability Database
CVE-2018-10839
PUBLISHED: 2018-10-16
Qemu emulator <= 3.0.0 built with the NE2000 NIC emulation support is vulnerable to an integer overflow, which could lead to buffer overflow issue. It could occur when receiving packets over the network. A user inside guest could use this flaw to crash the Qemu process resulting in DoS.
CVE-2018-13399
PUBLISHED: 2018-10-16
The Microsoft Windows Installer for Atlassian Fisheye and Crucible before version 4.6.1 allows local attackers to escalate privileges because of weak permissions on the installation directory.
CVE-2018-18381
PUBLISHED: 2018-10-16
Z-BlogPHP 1.5.2.1935 (Zero) has a stored XSS Vulnerability in zb_system/function/c_system_admin.php via the Content-Type header during the uploading of image attachments.
CVE-2018-18382
PUBLISHED: 2018-10-16
Advanced HRM 1.6 allows Remote Code Execution via PHP code in a .php file to the user/update-user-avatar URI, which can be accessed through an "Update Profile" "Change Picture" (aka user/edit-profile) action.
CVE-2018-18374
PUBLISHED: 2018-10-16
XSS exists in the MetInfo 6.1.2 admin/index.php page via the anyid parameter.