Security firm Eset has uncovered a malicious cyber campaign using a backdoor exploit in Apache web servers to herd web users to sites carrying Blackhole exploit packs. It will be difficult to assess the dangers and actions of specific compromised systems if only the binary is found and the active shared memory is not. Zwienenberg said the compromised servers are being used to drive web traffic to a number of malicious websites containing malware and exploits from the Blackhole exploit kit. The campaign has already compromised hundreds of Apache servers, meaning that thousands of websites could potentially have been affected.