Cisco Talos has discovered a new malware campaign that drops the sophisticated information-stealing trojan called “Agent Tesla,” and other malware such as the Loki information stealer. Initially, Talos’ telemetry systems detected a highly suspicious document that wasn’t picked up by common antivirus solutions. However, Threat Grid, Cisco’s unified malware analysis and threat intelligence platform, identified the unknown file as malware. The adversaries behind this malware use a well-known exploit chain, but modified it in such a way so that antivirus solutions don’t detect it.

https://blog.talosintelligence.com/2018/10/old-dog-new-tricks-analysing-new-rtf_15.html#more