Dark Reading is part of the Informa Tech Division of Informa PLC

This site is operated by a business or businesses owned by Informa PLC and all copyright resides with them.Informa PLC's registered office is 5 Howick Place, London SW1P 1WG. Registered in England and Wales. Number 8860726.

Threat Intelligence

Xori Adds Speed, Breadth to Disassembler Lineup

A new open source tool, introduced at Black Hat USA, places a priority on speed and automation.

One of the problems in malware analysis is that there's just so much malware to analyze. An automated dis-assembler would help, but that would require writing an automated disassembler — which is what Amanda Rousseau and Rich Seymour did when they built Xori.

In their Black Hat USA presentation, Rousseau and Seymour described the reasoning behind writing Xori, the process of building the software — and the results that come from the effort. "I'm constantly looking at tons and tons of samples and I need to reverse them fast," said Rousseau, senior malware researcher at Endgame, in an interview before the conference. When told by her boss that there were a thousand samples to be analyzed, she decided that automation was the only real answer.

Rousseau enlisted Seymour, a senior data scientist and Endgame, to help with development. He began, he said, with the parser. "I started writing that parser while Amanda was working on disassembly — what you can do on just raw bytes — and we sort of met in the middle," he explained.

Speed, in both process and execution, was a primary objective of Xori, and Seymour said that they were successful in that objective. "Xori can process a thousand samples on a five-year-old computer I had under my desk in 20 minutes," he said, noting that it's not doing complete analysis, but what it is doing is disassembly in far less than the six hours per sample earlier methods required. "It can process [samples] at about a second per sample," he said.

The processing results in a GUI output that presents the sample as a flowchart, or sequence of boxes that show the elements of the malware and the connections between them. Xori doesn't stop there, however. "Besides making that flowchart for you, it also tries to enhance and annotate as much of the code as possible so you don't have to really get into the actual assembly instructions themselves unless you really have to," Seymour explained.

Getting to this point required considerable effort. Asked about the work, Rousseau laughed, saying, "Many, many nights! I couldn't turn off my brain. Every day from 9 am until, oh, 10 pm, doing manual verification, learning the language, learning Rust, period, and trying to learn and trying to read the Intel manual," she said.

Rust itself was a choice that had implications for Rousseau. "It kind of started under the Mozilla umbrella, but it's since blossomed into a really great language and community that rides the line between strict type safety and academic languages, and then sort of the classic C/C++ type programming," she explained.

One major difference between Xori and other disassemblers is that Rousseau and Seymour wrote their tool to provide basic screening of as many samples, in as short a time, as possible. Other disassemblers tend to focus on going deeply into a single sample, no matter how long that effort takes. Now, Rousseau said, "It'll be good to put this out there as open source. Hopefully folks will not be afraid to contribute because I think it really does have a lot of potential."

Related content:

Learn from the industry's most knowledgeable CISOs and IT security experts in a setting that is conducive to interaction and conversation. Early bird rate ends August 31. Click for more info

Curtis Franklin Jr. is Senior Editor at Dark Reading. In this role he focuses on product and technology coverage for the publication. In addition he works on audio and video programming for Dark Reading and contributes to activities at Interop ITX, Black Hat, INsecurity, and ... View Full Bio

Comment  | 
Print  | 
More Insights
Comments
Newest First  |  Oldest First  |  Threaded View
Where Businesses Waste Endpoint Security Budgets
Kelly Sheridan, Staff Editor, Dark Reading,  7/15/2019
US Mayors Commit to Just Saying No to Ransomware
Robert Lemos, Contributing Writer,  7/16/2019
Register for Dark Reading Newsletters
White Papers
Video
Cartoon Contest
Current Issue
Building and Managing an IT Security Operations Program
As cyber threats grow, many organizations are building security operations centers (SOCs) to improve their defenses. In this Tech Digest you will learn tips on how to get the most out of a SOC in your organization - and what to do if you can't afford to build one.
Flash Poll
The State of IT Operations and Cybersecurity Operations
The State of IT Operations and Cybersecurity Operations
Your enterprise's cyber risk may depend upon the relationship between the IT team and the security team. Heres some insight on what's working and what isn't in the data center.
Twitter Feed
Dark Reading - Bug Report
Bug Report
Enterprise Vulnerabilities
From DHS/US-CERT's National Vulnerability Database
CVE-2018-17210
PUBLISHED: 2019-07-20
An issue was discovered in PrinterOn Central Print Services (CPS) through 4.1.4. The core components that create and launch a print job do not perform complete verification of the session cookie that is supplied to them. As a result, an attacker with guest/pseudo-guest level permissions can bypass t...
CVE-2019-12934
PUBLISHED: 2019-07-20
An issue was discovered in the wp-code-highlightjs plugin through 0.6.2 for WordPress. wp-admin/options-general.php?page=wp-code-highlight-js allows CSRF, as demonstrated by an XSS payload in the hljs_additional_css parameter.
CVE-2019-9229
PUBLISHED: 2019-07-20
An issue was discovered on AudioCodes Mediant 500L-MSBR, 500-MBSR, M800B-MSBR and 800C-MSBR devices with firmware versions F7.20A to F7.20A.251. An internal interface exposed to the link-local address 169.254.254.253 allows attackers in the local network to access multiple quagga VTYs. Attackers can...
CVE-2019-12815
PUBLISHED: 2019-07-19
An arbitrary file copy vulnerability in mod_copy in ProFTPD up to 1.3.5b allows for remote code execution and information disclosure without authentication, a related issue to CVE-2015-3306.
CVE-2019-13569
PUBLISHED: 2019-07-19
A SQL injection vulnerability exists in the Icegram Email Subscribers & Newsletters plugin through 4.1.7 for WordPress. Successful exploitation of this vulnerability would allow a remote attacker to execute arbitrary SQL commands on the affected system.