The ongoing patent battle between Trend Micro and Barracuda Networks — a case that has galvanized the Open Source community in defense of the ClamAV project — took a new turn yesterday as Barracuda filed a coutersuit against Trend Micro seeking damages for infringement of their own set of patents.

Barracuda, which was sued over its use of the Open Source ClamAV software for virus scanning at the gateway, described the need for a countersuit as an "unfortunate" but necessary step. The patents involved in the countersuit were purchased from IBM and cover spam filtering, virus protection, and intrusion detection. Barracuda was also quick to thank the Open Source community for assisting in the search for prior art to invalidate the Trend Micro patent — so grateful, in fact, that they have committed themselves to donate any proceeds from the litigation to the Open Source community. That day is likely far off, though, as the parties are still in discovery and if it follows what we've seen in other cases, Barracuda won't have their day in court for months, possibly years.