Was Birdsall Muller LLC hit by ransomware?

Birdsall Muller LLC was listed by the Cicada3301 ransomware operation (United States), 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 Cicada3301 ransomware group?

Cicada3301 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 Birdsall Muller LLC breach?

Cicada3301 published data attributed to Birdsall Muller LLC (~60 GB). Darkfield captured the leak post and a screenshot of the listing.

Ransomware victim disclosure

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Birdsall Muller LLC

Claimed by Cicada3301 · listed 1 year ago

60 GB

Data size

16m

Age

since listed · data leaked

Status timeline

ListedFeb 25, 2025
Data leakeddate unknown

At a glance

Group: Cicada3301
Status: Data leaked
Country: United States
Listed on leak site: Feb 25, 2025
Data size: 60 GB

About the victim

AI dossier — public-source company profile

Birdsall Muller LLC is a criminal defense law firm based in Milwaukee, Wisconsin, serving clients across multiple Wisconsin counties including Milwaukee, Dane, Kenosha, Racine, and Sheboygan. The firm specializes in criminal defense across a broad range of practice areas including drug crimes, DUI, federal crimes, homicide, sex crimes, and white-collar offenses.

Industry: Legal Services & Criminal Defense
Address: Milwaukee, Wisconsin, United States

Attack summary

Severity: high — Law firm data breach involving 60 GB of exfiltrated data. Criminal defense law firms hold highly sensitive privileged attorney-client communications, case strategies, and client PII (including potentially vulnerable criminal defendants). This constitutes confirmed exfiltration of regulated/sensitive professional data at significant scale, though the absence of proof screenshots suggests the threat post may be incomplete or early-stage.

Cicada3301 claims to have exfiltrated 60 GB of data from Birdsall Muller LLC. The group published the data but provided no additional details about what was encrypted, exfiltrated, or the specific data types compromised.

high

Data the group says was taken

AI dossier — extracted from the leak post

Client case files
Attorney work product
Client communications
Legal documents
Billing records

What the group claims

Status: 29d 22h 26m 19s - Size Data: 60 GB

Sources

Victim sitebirdsall-law.com
Leak posthttp://cicadabv7vicyvgz5khl7v2x5yygcgow7ryy6yppwmxii4eoobdaztqd.onion/1nxwju0hd4fhjzeae3a2a6xihkuqv0t4

Source

Indexed 1 year 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 Cicada3301

Cicada3301 is a recently emerged ransomware group that began operations in June 2024, primarily motivated by financial gain through extortion activities targeting organizations across multiple sectors. The group's origin and affiliations remain largely undocumented in public threat intelligence reporting, with limited information available regarding their operational structure or potential connections to other cybercriminal organizations. Based on observed targeting patterns, Cicada3301 has demonstrated a preference for attacking business services, technology, manufacturing, and financial sector organizations, with their operations concentrated primarily in English-speaking countries including the United States, United Kingdom, and Canada, as well as extending to Spain and Singapore. The group has successfully compromised approximately 75 known victims since their emergence, though specific details regarding their attack methodologies, initial access vectors, encryption techniques, and extortion tactics have not been extensively documented in publicly available threat intelligence reports from major cybersecurity firms or government agencies. Given the limited public documentation available from CISA, FBI, Mandiant, or other reputable security researchers, the group's current operational status, technical capabilities, and specific attack infrastructure remain largely uncharacterized in open-source intelligence reporting. As of the most recent observations, Cicada3301 appears to remain active in conducting ransomware operations, though comprehensive analysis of their tactics, techniques, and procedures awaits more detailed public reporting from established threat intelligence sources. The group has been linked to 75 public disclosures across our corpus. First observed on a leak site on June 20, 2024; most recent post September 4, 2025. The operation is currently inactive.

Timeline of this disclosure

February 25, 2025Birdsall Muller LLC listed by Cicada3301on the group's public leak site

Data size: 60 GB

Other recent disclosures by Cicada3301

Cicada3301 has been linked to 75 public victims on Darkfield. A sample of the most recent:

See the full Cicada3301 dossier →

Sector and geography

Geographically, Birdsall Muller LLC is reported in United States, a country with 11,033 ransomware disclosures in our corpus.

If your organisation is affected

A listing by Cicada3301 means Birdsall Muller LLC 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 Cicada3301'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.