North Korea-linked threat actor Kimsuky has unleashed a novel Golang-based information stealer dubbed “Troll Stealer,” suspected to be part of a targeted data theft campaign. This new malware variant, detected by South Korean cybersecurity firm S2W, exhibits similarities with known Kimsuky-associated malware families, such as AppleSeed and AlphaSeed. Notably, Kimsuky is notorious for its aggressive pursuit of sensitive information to advance North Korea’s strategic interests, leading to sanctions from the U.S. Treasury Department’s Office of Foreign Assets Control (OFAC).
Troll Stealer’s deployment involves spear-phishing attacks targeting South Korean entities, with the malware often concealed within a dropper masquerading as a legitimate security program installation file. A significant aspect of Troll Stealer is its capability to pilfer GPKI folders from infected systems, suggesting a strategic shift or collaboration with other threat actors familiar with Kimsuky’s modus operandi. Additionally, signs indicate potential association with a Go-based backdoor known as “GoBear,” which also exhibits functionality aligned with Kimsuky’s objectives, albeit with enhancements like SOCKS5 proxy support.
The discovery of Troll Stealer underscores the persistent and evolving threats posed by state-sponsored cyber actors like Kimsuky, necessitating continuous vigilance and robust cybersecurity measures. As Kimsuky adapts its tactics to circumvent defenses and maximize impact, organizations, particularly those in South Korea and sensitive sectors, must remain proactive in defending against such sophisticated threats. Collaboration between cybersecurity firms and governmental agencies is essential to identify, mitigate, and attribute cyberattacks, ultimately safeguarding critical infrastructure and sensitive information from malicious actors.
