Was ActionAid / TACOSA hit by ransomware?

ActionAid / TACOSA was listed by the medusalocker ransomware operation (United Kingdom), and stolen data was published on the group's leak site. Darkfield tracks this disclosure with the original leak post, screenshot and group context.

Who is the medusalocker ransomware group?

medusalocker is a ransomware operator tracked by Darkfield. See the full operator dossier for its known victims, sectors targeted, IOCs and leak-site infrastructure.

What data was leaked in the ActionAid / TACOSA breach?

medusalocker published data attributed to ActionAid / TACOSA. Darkfield captured the leak post and a screenshot of the listing.

Ransomware victim disclosure

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ActionAid International

listed as ActionAid / TACOSA · Claimed by Medusalocker · listed 1 month ago

40d

Age

since listed · data leaked

Status timeline

ListedMay 5, 2026
Data leakeddate unknown

At a glance

Group: Medusalocker
Status: Data leaked
Country: United Kingdom
Sector: Public Sector
Listed on leak site: May 5, 2026

About the victim

AI dossier — public-source company profile

ActionAid International is a global federation NGO working to combat poverty and injustice. The organization operates teams across multiple continents with a focus on women's rights, land and climate issues, politics and economics, and emergency response. They maintain operations in Africa, Asia, Oceania, Europe, and the Americas.

Industry: International Non-Governmental Organization (NGO) / Humanitarian Aid

Attack summary

Severity: high — ActionAid is a major international NGO with significant humanitarian operations and donor networks. Compromise of such an organization poses risks to vulnerable populations they serve, their staff, and their donor base. The involvement of government domains (Tanzania immigration) elevates concern, though the exact data scope is unclear.

MedusaLocker claims to have compromised ActionAid International and associated entities including TACOSA and Tanzania immigration infrastructure. The group has published data but specific details on exfiltration scope or encryption status are not elaborated in the available post excerpt.

high

Data the group says was taken

AI dossier — extracted from the leak post

organizational records
donor information
operational documents
staff data

What the group claims

NGO sector. Domains: actionaid.org, tacosa.org.za, immigration.go.tz.

Sources

Victim siteactionaid.org
Leak posthttp://t33zoj4qwv455fog7qnb2azi5xcdxkixughmmduzbw2rtdgryqfbh6id.onion/company/actionaid-tacosa/

Source

Indexed 1 month ago

This page surfaces a public ransomware disclosure indexed by Darkfield. Original posts come from the operator's own leak site; we cross-check against ransomware.live, RansomLook and RansomWatch where applicable. Share this URL freely.

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Disclosure context

About medusalocker

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.

Timeline of this disclosure

May 5, 2026ActionAid / TACOSA listed by medusalockeron the group's public leak site

Other recent disclosures by medusalocker

medusalocker has been linked to 67 public victims on Darkfield. A sample of the most recent:

See the full medusalocker dossier →

Sector and geography

This disclosure adds to ransomware activity in the Public Sector sector, which has 466 disclosures indexed across all operators we track. Geographically, ActionAid / TACOSA is reported in United Kingdom, a country with 372 ransomware disclosures in our corpus.

If your organisation is affected

A listing by medusalocker means ActionAid / TACOSA 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, NCSC (United Kingdom), 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.