The KeyBoy attacker group is using publicly available exploit code for two Microsoft security flaws to infect vulnerable machines with malware.

Researchers at AlienVault recently observed a new campaign launched by the KeyBoy attacker group, which has been active since at least 2013. In this latest operation, the group sent a phishing email to India’s ambassador to Ethiopia from an email address at nic.in, India’s National Informatics Centre.

The email arrived with an attachment that executed a script containing the public exploit code for CVE-2017-0199, a Microsoft vulnerability that allows attackers to execute arbitrary code using a crafted document. Other documents contained an exploit generator for CVE-2017-8570, which bypasses Microsoft’s patch for CVE-2017-0199.

Exploiting Known Vulnerabilities to Install TSSL and Titan Malware

Upon launching the exploit code, the script downloaded malware known as TSSL. Citizen Lab observed variants of TSSL that came with the FakeRun loader and the TClient backdoor, which allowed the attacker group to download additional threats and maintain a presence on an infected system.

AlienVault also detected KeyBoy’s ongoing distribution of Titan, Android malware that is capable of collecting an infected user’s data and performing instructions as a superuser, according to researchers at Lookout.

These KeyBoy attacks weren’t the first to involve exploit code for CVE-2017-0199 and CVE-2017-8570. FireEye observed attackers abusing CVE-2017-0199 with malicious Microsoft Office RTF documents in April 2017, and Trend Micro detected campaigns exploiting that same flaw via PowerPoint slideshows several months later. In April 2018, Zscaler identified a campaign that leveraged exploit code for CVE-2017-8570 to distribute LokiBot.

The Key to Stopping KeyBoy Attacks

Organizations can protect themselves against KeyBoy’s campaigns and similar operations by practicing intelligent vulnerability management. This approach requires organizations to create an effective vulnerability assessment process and use it to evaluate flaws based on their level of risk. Instead of patching everything as quickly as possible, organizations can use these vulnerability assessments to determine the order in which bugs should be patched.

Sources: AlienVault, Citizen Lab, Lookout, FireEye, Trend Micro, Zscaler