The Pierce County Library System this week confirmed it notified 336,826 people of an April 2025 data breach that compromised names and dates of birth.
The cyber attack disrupted many library services in April and May 2025, including access to the library catalog, self-checkout, applications for library cards, printing, and access to library computers.
Ransomware gang Inc took credit for the breach in May, saying it stole 1.94 TB of data. To prove its claim, Inc posted images of driver’s licenses, passports, and internal library documents that Inc says it stole from Pierce County Libraries.
We do not yet know if Pierce County Libraries paid a ransom, how much Inc demanded, or how attackers breached the libraries’ network. Comparitech contacted Pierce County Libraries for comment and will update this article if it replies.
“The investigation determined PCLS’ environment was subject to unauthorized access and between April 15 and April 21, 2025, certain files were copied and taken,” says Pierce County Libraries’ notice (PDF) to victims.
PCLS is offering eligible victims one year of free credit monitoring through IDX.
Who is Inc Ransomware?
Inc Ransomware emerged in July 2023 and targets a wide range of victims in healthcare, education, and government. Its methods involve spear phishing and exploiting known vulnerabilities in software. Once infected, Inc’s malware both steals data and locks down computer systems until a ransom is paid to unlock them.
Inc has claimed responsibility for 103 confirmed ransomware attacks since it began, compromising nearly 8 million records. Another 248 of Inc’s claims have yet to be confirmed by the targeted organizations.
Inc’s largest attack was against Ahold Delhaize, which recently began notifying 2.2 million people of the ensuing breach.
Inc has taken credit for 17 attacks on government agencies including the city of Durant, OK; Thomasville, NC; and Tonga’s Ministry of Health.
In 2025 to date, Inc took credit for 21 confirmed attacks and 116 unconfirmed.
Ransomware attacks on US government
Comparitech researchers have logged 36 confirmed ransomware attacks on US government agencies thus far in 2025, plus another 36 unconfirmed claims that haven’t been acknowledged by the attacked organizations. The confirmed attacks compromised more than 349,000 records, with the majority of those from Inc’s attack on PCLS, which is the sixth-largest such attack on a government entity since 2018.
Other ransomware attacks on US government entities confirmed in June include:
- Fort Bend County Libraries reported a March 2025 ransomware attack by unknown cybercriminals
- Mower County, MN reported a ransomware attack by an unknown group earlier this month
- Taos County reported a suspected ransomware attack claimed by Kairos
- Green River reported a ransomware attack by unknown attackers
Ransomware attacks on US government agencies and departments like libraries can both steal data and lock down computer systems. The attacker then demands a ransom to delete the stolen data and in exchange for a key to recover infected systems. If the target doesn’t pay, it could take weeks or even months to restore systems, data could be lost forever, and people whose data was stolen are put at greater risk of fraud.
About Pierce County Libraries
The Pierce County Library System consists of 19 libraries and an online catalog in the second largest county in Washington.
