Microsoft’s Edge browser has replaced Internet Explorer in almost every regard, but some exceptions remain. One of those, deep inside Microsoft Word, was exploited by a North-Korean-backed group this fall, Google security researchers claim.
It’s not the first time the government-backed APT37 has utilized Internet Explorer’s lingering presence, as Google’s Threat Analysis Group (TAG) notes in a blog post. APT37 has had repeated success targeting South Korean journalists and activists, plus North Korean defectors, through a limited but still successful Internet Explorer pathway.
The last exploit targeted those heading to Daily NK, a South Korean site dedicated to North Korean news. This one involved the Halloween crowd crush in Itaewon, which killed at least 151 people. A Microsoft Word .docx document, named as if it were timed and dated less than two days after the incident and labeled “accident response situation,” started circulating. South Korean users began submitting the document to the Google-owned VirusTotal, where it was flagged with CVE-2017-0199, a long-known vulnerability in Word and WordPad.