MedusaLocker is a ransomware operation first publicly documented around 2019, though the activity cluster reflected in this dataset shows observed campaigns beginning in November 2022, driven primarily by financial motivation with no known ideological or hacktivist agenda. The group is believed to operate out of or with ties to Eastern Europe, functioning as a Ransomware-as-a-Service model that allows affiliates to deploy the ransomware in exchange for a share of ransom proceeds, a structure documented in a joint advisory published by CISA, FBI, FinCEN, and HHS in June 2022. MedusaLocker actors typically gain initial access through phishing emails, exploitation of vulnerable Remote Desktop Protocol configurations, and compromised network devices, subsequently deploying the ransomware payload which encrypts victim files using AES-256 combined with RSA-2048 encryption while also exfiltrating sensitive data prior to encryption to enable double extortion pressure. Based on available telemetry, the group has claimed at least 67 known victims, with targeting concentrated heavily in the United States, United Kingdom, Brazil, France, and Israel, spanning sectors including business services, manufacturing, technology, and education, consistent with the opportunistic rather than highly selective targeting pattern characteristic of RaaS affiliate programs. As of the time of writing, MedusaLocker remains an active threat with no confirmed law enforcement disruption, takedown operation, or confirmed rebrand publicly attributed to the group by major intelligence or law enforcement agencies. The group has been linked to 67 public disclosures across our corpus. First observed on a leak site on November 15, 2022; most recent post May 5, 2026. The operation is currently active.
Sector and geography
This disclosure adds to ransomware activity in the Business Services sector, which has 3,795 disclosures indexed across all operators we track. Geographically, SIT Group / Robusta is reported in Italy, a country with 202 ransomware disclosures in our corpus.
If your organisation is affected
A listing by medusalocker means SIT Group / Robusta appeared on a ransomware extortion site and data attributed to it has been published. If this is your organisation, or a supplier you depend on, the priority is to confirm the intrusion and contain it before the window to act closes.
- Engage your incident-response team and preserve forensic evidence before remediating — do not wipe affected systems first.
- Force a password reset and revoke active sessions for exposed accounts; rotate any credentials, API keys or certificates that may have been in the stolen data.
- Assess regulatory notification duties (GDPR, NIS2, sector regulators) — many carry a 72-hour reporting clock from awareness.
- Report the incident to your national CERT, CSIRT Italia (Italy), as required for your jurisdiction.
- Monitor for the data appearing on medusalocker's leak site and across paste and breach channels, and brief downstream partners who may be exposed through you.
How we know this. Darkfield monitors public ransomware leak sites continuously, archiving every new disclosure and the data later released against the victim. Each entry on this page is sourced from the operator's own publication and cross-checked against complementary OSINT feeds (RansomLook, ransomware.live, RansomWatch). We do not collect or host stolen data — only the metadata, timestamps and screenshots needed to make the public disclosure searchable and accountable. Records here are corrected when the original post is edited, retracted, or merged with another disclosure.
