|Type||Subsidiary of Barracuda Networks|
|Products||Anti-virus, Anti-spyware, Web filtering|
Purewire, launched in November 2007, provides an in-the-cloud security service for web traffic. Its services block malware and secure the use of the Web. The Purewire management team includes former employees of CipherTrust, which was acquired by Secure Computing and IBM Internet Security Systems. The company competes with similar services offered by MessageLabs, ScanSafe, Webroot, Websense and Zscaler.
In January 2009, Purewire acquired Opinity, an online reputation management system. 
- "Atlanta-based Security firm launches Purewire Trust to vet Web sites, people and software". LocalTechWire.com. Retrieved 2009-04-19.
- "Executive Team". Purewire. Retrieved 2009-04-19.
- "Security firm launches Purewire Trust to vet web sites, people and software". The Industry Standard. Retrieved 2009-04-19.
- "Purewire Acquires Opinity Reputation Service". Reuters. 2009-01-29. Retrieved 2009-04-19.
- "Barracuda gobbles up SaaS security start-up Purewire". Network World. Retrieved 2009-10-13.