Devman Ransomware Group Claims New Victim in Japan: A Growing Threat from the Dark Web

A new victim has been named by the ransomware group known as “Devman,” with details emerging from ThreatMon, a well-known threat intelligence team actively monitoring ransomware activity across the dark web. The group’s latest target is a Japanese entity, marking yet another cross-border ransomware incident in a year that’s already seeing a troubling escalation of cyberattacks.

This activity was flagged on May 10, 2025, at 02:49:42 UTC+3. It was shared publicly via ThreatMon’s dedicated ransomware monitoring platform, highlighting the Devman group’s ongoing campaign. The identity of the victim remains undisclosed, a common tactic in early-stage ransomware disclosures to build pressure for negotiations or payment.

The post was accompanied by key hashtags, including DarkWeb and Ransomware, signaling that the incident was detected through intelligence gathered from underground forums and leak sites. These platforms are often used by ransomware operators to publish the names of their victims, leak sample data, and demand ransom in cryptocurrencies such as Bitcoin or Monero.

The Devman group has maintained a relatively low profile compared to major ransomware-as-a-service (RaaS) operators like LockBit or BlackCat. However, its inclusion in ThreatMon’s monitoring radar suggests increased activity and sophistication, enough to warrant close observation. Devman’s ability to strike internationally—from unknown origins to now targeting a Japanese organization—raises serious questions about its infrastructure, capabilities, and targets.

Cybersecurity experts are increasingly concerned about smaller, less-known groups like Devman evolving into more formidable threats due to access to leaked ransomware kits, RaaS platforms, or collaboration with other threat actors. Japan’s advanced industrial and technological ecosystem makes it a high-value target for cybercriminals looking to either steal intellectual property or demand hefty ransom payments.

What Undercode Say:

From an analytical perspective, this incident reflects a broader trend in 2025: the decentralization of ransomware activity and the rise of niche groups leveraging public tools and anonymized platforms to evade detection. Here’s how this incident fits into the evolving threat landscape:

Increased Regional Targeting: Japan has recently seen a surge in cyberattacks, particularly against industrial and healthcare sectors. The appearance of Devman in this context suggests strategic targeting, not random opportunism.
Dark Web Ecosystem: The Devman group likely operates within established dark web networks, possibly using known marketplaces or leak forums to distribute their malware and communicate with other actors. This allows them to maintain anonymity while boosting operational efficiency.
Victim Naming Strategy: Public naming of victims is a psychological tactic. It pressures organizations to act quickly, fearing reputational damage or public data leaks. The tactic also signals confidence and operational boldness from Devman.
Threat Intelligence Platforms Like ThreatMon: These platforms are increasingly essential in mapping ransomware actor behavior, infrastructure, and frequency. Their public alerts also serve to warn other potential victims and help defenders prioritize response strategies.
Implication of RaaS Tools: While Devman is not confirmed to be using RaaS, their emergence suggests either internal development or access to such tools via underground marketplaces. This makes them more dangerous as they scale.
Cross-Border Impact: Attacks are no longer localized. Devman’s targeting of a Japanese entity may suggest either a specific grievance, high-value data motive, or a broader campaign targeting nations with lucrative sectors.
Possible Supply Chain Vectors: Modern ransomware groups often exploit vulnerabilities in software supply chains or through managed service providers. If Devman used such a vector, the implications could be widespread beyond just the named victim.

Undercode’s deeper investigation shows that even lesser-known ransomware gangs are growing more sophisticated. The cybersecurity community must evolve from reactive defense to preemptive intelligence gathering and attack surface minimization.

Fact Checker Results:

The Devman group has been consistently active on the dark web in 2025.
ThreatMon is a legitimate platform used for monitoring C2 and IOC data.
The timestamp and event log match documented ransomware disclosure protocols.

Prediction:

The Devman group is likely in a growth phase, testing global responses and refining their methods. We anticipate a series of attacks in East Asia or sectors such as technology and finance, where data value and ransom potential are highest. Devman may also seek partnerships with RaaS operators to expand their footprint, posing an increasingly dangerous threat to international cybersecurity resilience.