Pierluigi Paganini December 03, 2013

Security experts at Trend Micro detected a new variant of AutoCAD Malware that leaves victims hackable for further cyber attacks.

Malware researchers at Trend Micro spotted AutoCAD Malware codenamed ACM_SHENZ.A. It’s not first time that a malware was specifically designed to steal AutoCAD project, last years security specialists at ESET detected a malicious code dubbed “ACAD/Medre.A” specialized in the theft of AutoCAD files. The virus has been developed to steal the blueprints from private companies mostly based in Peru according the security firm ESET, the virus was able to locate AutoCAD file on infected machines and to send them via e-mail to accounts provided by two Chinese internet firms, 163.com and qq.com

The choice to steal this particular type of file is motivated by the consideration that AutoCAD is one of the most used application for 2D and 3D computer-aided design (CAD) and drafting and it is widespread in principal industries.

Once infected the AutoCAD Malware creates an administrative account and unlocks the ports with the (SMB) Server Message Block protocol.

” It appears to be a legitimate AutoCAD component with a .FAS extension, but on analysis it actually opens up systems to exploits, specifically those targeting old vulnerabilities.” “It then creates network shares for all drives from C: to I:. It then opens four ports on the system: ports 137-139, and port 445. “reported the blog post published by Trend Micro.

The administrative account lets attacker to serve malicious code and steal documents from victims’PC , the cybercriminals behind the malware exploit unpatched SMB flaw to open the SMB ports and control the targeted system. The ports opened provides access to files, printers, serial ports, and miscellaneous communications between nodes on a network running on Windows.

“By opening the ports, exploits that target SMB can successfully run on affected systems, provided that the relevant vulnerabilities have not yet been patched. Security bulletins that cover the SMB vulnerabilities include MS10-020and MS11-043.”

Analyzing the structure of the agent the experts believe that ACM_SHENZ.A may have been designed to launch further attacks.
The AutoCAD Malware also allows attackers to disable certain AutoCAD functions and modify all AutoCAD files to spread malware.

The AutoCAD Malware ACM_SHENZ.A is quite different from the one detected by ESET last year, the malicious agent discovered by Trend Micro was designed with leaves the compromised machine open for further exploitation and could be used for long term cyber espionage operation.

Global VP of Trend Micro’s Security Research, Rik Ferguson, to the answer if the two malware are different replied:

“Yep, ‘its different’.”

As usual the best way to keep the system protected  from infection of AutoCAD Malware ACM_SHENZ. A is to keep updated anti-virus software and fix all unpatched vulnerabilities to reduce the surface of attack of the cyber threat.