North Korean threat group APT37 was able to exploit an Internet Explorer zero-day vulnerability to deploy documents loaded with malware as part of its ongoing campaign targeting users in South Korea, including defectors, journalists, and human rights groups.

Google's Threat Analysis Group (TAG) found the zero-day flaw in the Internet Explorer JScript engine in late October, tracked under CVE-2022-41128, and now reports that Microsoft was responsive and has issued applicable patches.

To lure in potential victims, the malicious documents referenced the deadly crowd crushing incident in Seoul that happened during Halloween celebrations on Oct. 29.

"This incident was widely reported on, and the lure takes advantage of widespread public interest in the accident," the TAG team reported. "This is not not the first time APT37 has used Internet Explorer 0-day exploits to target users."