**Overview:** Netwalker is a financially motivated ransomware group that emerged in January 2020, rapidly establishing itself as one of the more prolific ransomware operations during the height of the COVID-19 pandemic. The group primarily targets organizations for financial gain through encryption and extortion tactics.
**Origin & Affiliation:** Netwalker is believed to operate as a Ransomware-as-a-Service (RaaS) model with suspected Russian-speaking affiliates, though definitive attribution to a specific nation-state remains unconfirmed by law enforcement agencies. The group has operated independently without established links to other major ransomware families.
**Attack Methodology:** Netwalker affiliates typically gained initial access through exposed Remote Desktop Protocol (RDP) services, phishing emails, and exploitation of unpatched vulnerabilities in public-facing applications. The group employed double extortion tactics, exfiltrating sensitive data before deploying their ransomware payload, and maintained a leak site to pressure victims into paying ransoms by threatening to publish stolen information.
**Notable Campaigns:** The group notably targeted healthcare organizations during the COVID-19 pandemic, including attacks on hospitals and healthcare facilities, drawing significant attention from law enforcement and cybersecurity agencies. Netwalker was responsible for high-profile attacks across multiple critical infrastructure sectors, with CISA and FBI issuing specific advisories warning organizations about the group's activities.
**Current Status:** Netwalker operations were significantly disrupted in January 2021 when international law enforcement actions led to the takedown of their infrastructure and the arrest of a key affiliate, effectively ending the group's active operations. The group has been linked to 26 public disclosures across our corpus. First observed on a leak site on January 31, 2020; most recent post December 12, 2020. The operation is currently inactive.
Sector and geography
This disclosure adds to ransomware activity in the Healthcare and Public Health sector, which has 52 disclosures indexed across all operators we track. Geographically, Olympia House (Petaluma) is reported in United States, a country with 7,392 ransomware disclosures in our corpus.
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.
