TA551 (also known as Shathak) is an email-based malware distribution campaign that often targets English-speaking victims. The campaign discussed in this blog has targeted German, Italian and Japanese speakers. TA551 has historically pushed different families of information-stealing malware like Ursnif and Valak. After mid-July 2020, this campaign has exclusively pushed IcedID malware, another information stealer.
This blog provides an overview of TA551, as well as previous activity from this campaign. We also examine changes from this campaign since our previous blog about TA551 pushing Valak in July 2020.