Cybersecurity researchers on Tuesday disclosed details of a sophisticated campaign that deploys malicious backdoors for the purpose of exfiltrating information from a number of industry sectors located in Japan.

Dubbed "A41APT" by Kaspersky researchers, the findings delve into a new slew of attacks undertaken by APT10 (aka Stone Panda or Cicada) using previously undocumented malware to deliver as many as three payloads such as SodaMaster, P8RAT, and FYAnti.

The long-running intelligence-gathering operation first came into the scene in March 2019, with activities spotted as recently as November 2020, when reports emerged of Japan-linked companies being targeted by the threat actor in over 17 regions worldwide.

The fresh attacks uncovered by Kaspersky are said to have occurred in January 2021. The infection chain leverages a multi-stage attack process, with the initial intrusion happening via abuse of SSL-VPN by exploiting unpatched vulnerabilities or stolen credentials.

Center to the campaign is a malware called Ecipekac ("Cake piece" in reverse, but with a typo) that traverses a four-layer "complicated loading schema" by making use of four files to "load and decrypt four fileless loader modules one after the other to eventually load the final payload in memory."

While the main purpose of P8RAT and SodaMaster is to download and execute payloads retrieved from an attacker-controlled server, Kaspersky's investigation hasn't yielded any clues as to the exact malware delivered on target Windows systems.

Interestingly, the third payload, FYAnti, is a multi-layer loader module in itself that goes through two more successive layers to deploy a final-stage remote access Trojan known as QuasarRAT (or xRAT).

"The operations and implants of the campaign ... are remarkably stealthy, making it difficult to track the threat actor's activities," Kaspersky researcher Suguru Ishimaru said. "The main stealth features are the fileless implants, obfuscation, anti-VM ,and removal of activity tracks."