The investigation described in this article started with one such file which caught our attention due to the various improvements it brought to this well-known infection vector.
A41APT is a long-running campaign with activities detected from March 2019 to the end of December 2020. Most of the discovered malware families are fileless malware and they have not been seen before.
In mid-2020, we realized that Lazarus was launching attacks on the defense industry using the ThreatNeedle cluster, an advanced malware cluster of Manuscrypt (a.k.a. NukeSped). While investigating this activity, we were able to observe the complete life cycle of an attack, uncovering more technical details and links to the group’s other campaigns.
While looking at the Sunburst backdoor, we discovered several features that overlap with a previously identified backdoor known as Kazuar. Our observations shows that Kazuar was used together with Turla tools during multiple breaches in past years.