Double Kill Vulnerability Integrated with RIG Exploit Kit

eSentire Threat Intelligence is aware of public reports indicating CVE-2018-8174 (a.k.a. Double Kill) has been integrated into web browser exploit kits.  eSentire Threat Intelligence assesses with medium confidence that this development poses an immediate threat to organizations where unpatched versions of Microsoft Windows 7 operating system are actively employed. Customers are advised to review Microsoft’s security guidance on this matter and apply relevant security updates.¹

Should widespread adoption and exploitation of this vulnerability emerge eSentire Threat Intelligence will reassess the severity of this threat.

What we’re doing about it

• esNETWORK rules have been deployed to detect active exploitation attempts
• esRECON plugins have been deployed to identify assets affected by this vulnerability
• eSentire Threat Intelligence is currently blocking observed network infrastructure associated with the RIG exploit kit and is monitoring the situation closely

What you should do about it

• After a business impact review, apply the relevant Microsoft security updates¹
• Ensure employees are aware of ongoing email and web-based threats

Additional information

Double Kill is a remote code execution vulnerability leveraging memory corruption inside Microsoft VBScript Engine.²

On May 25, 2018, security researcher Kafeine reported in a blog post³ that proof-of-concept code for CVE-2018-8174 against Internet Explorer 11 on Windows 7 had been integrated with web browser exploit kits. The post includes evidence that this proof-of-concept code has been integrated with the RIG exploit kit as of May 25. eSentire has not observed this activity across our customers.

RIG, like other exploit kits, first determines the vulnerabilities associated with the victim’s browser before redirecting them to the desired exploit. Successful exploitation can result in the installation of malicious code on the victim’s machine. Exploitation typically occurs without user interaction, and victims are often redirected silently from popular websites that have been compromised.

References:

[1] CVE-2018-8174 | Windows VBScript Engine Remote Code Execution Vulnerability
https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2018-8174

[2] Double Kill Zero-Day Vulnerability
https://www.esentire.com/security-advisories/doublekill-zero-day-vulnerability/

[3] CVE-2018-8174 (VBScript Engine) and Exploit Kits
https://malware.dontneedcoffee.com/2018/05/CVE-2018-8174.html