Cyber Criminals launching a massive payload campaign that exploit the vulnerability that existed in the WinRAR compression tool to compromise the target Windows System.

Since the vulnerability has been already patched, attacker aiming to exploit and compromise the unpatched vulnerable systems.

Researchers from checkpoint recently discovered this 19-year-old Remote Code Execution bug vulnerability in WinRAR UNACEV2.DLL allows attackers to take complete control of the vulnerable windows machine.

WinRAR is worlds most popular Compression tool that used over 500 million users around the world.


The vulnerability(CVE-2018-20250) resides the unacev2.dll that used in handling the ACE archive extraction. The ACE file format compiled using WinACE.

Similarly, cyber criminals already launched First Malware Campaign that Exploits WinRAR ACE vulnerability on Feb 5, 2019.

Exploiting WinRAR UNACEV2.DLL Vulnerability

Initially, Threat actors compressed the exploit payload using WinRAR and distributing to victims with the name of “Ariana_Grande-thank_u,next(2019)[320].rar”.

Malformed Archive

In this case, once users open the compressed payload using unpatched & vulnerable WinRAR then the malicious payload is created in the Startup folder.

Extracted Malware payload 

Along with the payload, researchers uncovered that the compressed file also contains non-malicious MP3 files which is one of the tactics attacker used to trick victims to drop the malicious payload.

According to McAfee research, “User Access Control (UAC) is bypassed after the payload gets executed, so no alert is displayed to the user. The next time the system restarts, the malware is run.”

Also, researchers uncovered over 100 unique payloads and still it’s counting, most of the sample primarily targeting the victims in U.S.

All the WinRAR users are advised to update the current patched version,
WinRAR 5.70 to avoid such attacks and also avoid to open the unknown files.

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Also Read:

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BALAJI is a Former Security Researcher (Threat Research Labs) at Comodo Cybersecurity. Editor-in-Chief & Co-Founder - Cyber Security News & GBHackers On Security.


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