The Sheppard Mullin cyberattack has prompted a former paralegal to file a proposed class action, alleging the Am Law 100 firm failed to safeguard sensitive personal information taken in an August breach that she says affected at least 1,000 people.
According to court filings, plaintiff Pena-Emilia Williams sued in the U.S. District Court for the Central District of California on Wednesday. The complaint asserts that names, Social Security numbers, and driver’s license and other government identification numbers were exposed, characterizing the theft as “a bell that cannot be unrung” for employees and clients.
Sheppard Mullin cyberattack disclosure
The firm notified the California attorney general’s office on Oct. 2 that an attorney was deceived through a social engineering scheme and provided documents to an unknown third party, according to the disclosure. The lawsuit claims the firm failed to adequately train personnel on cybersecurity and to maintain appropriate safeguards to prevent such incidents.
Williams, who worked as a paralegal at Sheppard, Mullin, Richter & Hampton from 2022 until March 2026, also contends the firm did not timely notify affected individuals as required under California law.
“Defendant had no effective means to prevent, detect, stop or mitigate breaches of its systems, thereby allowing cybercriminals unrestricted access to its employees’ and clients’ employees’ personally identifiable information,” Williams alleged in her Oct. 7 complaint.
Wave of data breach litigation
The filing places Sheppard Mullin among several major firms facing data breach suits this year. In July, Wilmer Cutler Pickering Hale and Dorr was sued in the U.S. District Court for the District of Columbia by a former client, a case that echoes broader concerns seen in matters like the ByteDance data scraping lawsuit.
In June, Fox Rothschild was sued in the U.S. District Court for the Eastern District of Pennsylvania. Representatives for Williams and for Sheppard Mullin did not respond to requests for comment on Thursday.