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Incident

Utility Trailer Manufacturing

Incident posture

Attack window
May 2021
Location
United States of America
Status
Historical
CIA posture
Available to members
Updated
2025-10-24 00:00

Linked entities

Victim
Utility Trailer Manufacturing
Threat actors
1 actor
Sources
1 source

Timeline

Occurred
May 2021
Discovered
Pending
Disclosed
Pending
Resolved
Pending

Summary

Utility Trailer Manufacturing experienced a cyberattack involving the Clop ransomware group, which resulted in the theft and public leak of over five gigabytes of sensitive employee data, including compensation claims, termination records, and tax documents. The incident temporarily disrupted some of the organization's systems, though it remains unclear whether data encryption occurred or if operations were restored via backups. The attackers publicly demonstrated compromised files on their leak site, confirming the exposure of highly sensitive personnel information.

Motives

Detailed motive labels are available to members.

2 motives

TTPs

Detailed technique labels are available to members.

2 techniques

Description

On or around May 13, 2021, Utility Trailer Manufacturing Company, a California-based manufacturer and one of the largest U.S. producers of trailers for the trucking industry, experienced a cyber incident. The company publicly acknowledged suffering a "cyber event" that temporarily disrupted some of its systems. The Clop ransomware gang claimed responsibility for the attack and subsequently leaked over 5 gigabytes of the company's data on their dark web leak site. As proof of their claims, Clop published screenshots displaying directory structures and sensitive employee records, including compensation claims, termination documents, and tax records. These leaked materials contained unredacted personal and financial information belonging to Utility Trailer employees, though specific employee counts were not disclosed in available reporting. The data exposure occurred despite Utility Trailer's systems reportedly being restored to operational status following the temporary disruption.

The incident exhibited characteristics consistent with Clop's operational patterns observed in previous attacks, including their involvement in the Accellion breach where they exfiltrated data without deploying encryption. While Utility Trailer's reference to system disruptions suggested potential file encryption, the company did not confirm whether ransomware deployment occurred or whether restoration relied on backups. Clop's actions aligned with their established double-extortion tactics, involving data theft followed by threats to publish stolen information unless payment was received. No information was disclosed regarding ransom demands, payments, or the full scope of compromised systems beyond the employee data samples visible in Clop's leak site screenshots. Utility Trailer provided no additional public statements beyond confirming the cyber event and temporary operational impact, leaving the attack vector, full data exposure extent, and final resolution status unverified in available sources.

Sources

Sources available to members: 1 source.

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