Qilin Ransomware Turns South Korean Msp Breach Into 28-victim...

South Korea's financial sector has been targeted by what has been described as a sophisticated supply chain attack that led to the deployment of Qilin ransomware.

"This operation combined the capabilities of a major Ransomware-as-a-Service (RaaS) group, Qilin, with potential involvement from North Korean state-affiliated actors (Moonstone Sleet), leveraging Managed Service Provider (MSP) compromise as the initial access vector," Bitdefender said in a report shared with The Hacker News.

Qilin has emerged as one of the most active ransomware operations this year, with the RaaS crew exhibiting "explosive growth" in the month of October 2025 by claiming over 180 victims. The group is responsible for 29% of all ransomware attacks, per data from NCC Group.

The Romanian cybersecurity company said it decided to dig deeper after uncovering an unusual spike in ransomware victims from South Korea in September 2025, when it became the second-most affected country by ransomware after the U.S., with 25 cases, a significant jump from an average of about 2 victims per month between September 2024 and August 2025.

Further analysis found that all 25 cases were attributed exclusively to the Qilin ransomware group, with 24 of the victims in the financial sector. The campaign was given the moniker Korean Leaks by the attackers themselves.

While Qilin's origins are likely Russian, the group describes itself as "political activists" and "patriots of the country." It follows a traditional affiliate model, which involves recruiting a diverse group of hackers to carry out the attacks in return for taking a small share of up to 20% of the illicit payments.

One particular affiliate of note is a North Korean threat actor tracked as Moonstone Sleet, which, according to Microsoft, has deployed a custom ransomware variant called FakePenny in an attack targeting an unnamed defense technology company in April 2024.

Then, earlier this February, a significant pivot occurred when the adversary was observed delivering Qilin ransomware at a limited number of organizations. While it's not exactly clear if the latest set of attacks was indeed carried out by the hacking group, the targeting of South Korean businesses aligns with its strategic objectives.

Korean Leaks took place over three publication waves, resulting in the theft of over 1 million files and 2 TB of data from 28 victims. Victim posts associated with four other entities were removed from the data leak site (DLS), suggesting

Source: The Hacker News