In late May, researchers drove out a team of China state hackers who over the previous seven months had exploited a critical vulnerability that gave them backdoors into the networks of a who’s who of sensitive organizations. Barracuda, the security vendor whose Email Security Gateway was being exploited, had deployed a patch starting on May 18, and a few days later, a script was designed to eradicate the hackers, who in some cases had enjoyed backdoor access since the previous October.

Source: Technology Lab – Ars Technica