Mamba is a ransomware group first observed in May 2020, operating with a financially motivated agenda and employing full-disk encryption techniques that distinguish it from many contemporary ransomware families. The group is notable for its use of DiskCryptor, a legitimate open-source disk encryption tool, to encrypt entire volumes rather than individual files, a methodology previously documented by the FBI in a May 2021 Flash Alert warning organizations — particularly in the healthcare and government sectors — about Mamba's destructive potential. Mamba has been linked to activity targeting organizations in the United States, with the healthcare sector identified as a primary focus based on available victimology data, though its overall known victim count remains limited in publicly disclosed reporting. The group's attack chain typically involves gaining initial access through compromised Remote Desktop Protocol (RDP) credentials, followed by deployment of DiskCryptor with attacker-controlled encryption keys, effectively rendering systems inoperable until a ransom is negotiated; notably, Mamba does not appear to consistently employ double extortion through data exfiltration in the manner of more prolific ransomware operations, making recovery dependent on decryption rather than preventing data leakage. No major high-profile campaigns or record ransom demands have been publicly attributed to Mamba by CISA, FBI, or major threat intelligence vendors, reflecting its relatively low operational tempo. Based on available public reporting, Mamba remains a low-to-moderate threat actor with limited documented activity, and no confirmed law enforcement disruption, rebrand, or dissolution has been publicly reported as of available intelligence. The group has been linked to 1 public disclosures across our corpus. First observed on a leak site on May 7, 2020. The operation is currently inactive.
Also tracked as: HDDCryptor.
Sector and geography
This disclosure adds to ransomware activity in the Healthcare sector, which has 2,600 disclosures indexed across all operators we track. Geographically, Unnamed health care company is reported in United States, a country with 3,115 ransomware disclosures in our corpus.
If your organisation is affected
A listing by mamba means Unnamed health care company 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, CISA (United States), as required for your jurisdiction.
- Monitor for the data appearing on mamba'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.
