Most of the hosting account hack occurs due to infected computer. No one single anti-malware application will catch 100% of all malware on-the-wild, so scans with two or more reputable malware scanners to protect your computer. If unsure on which program to use to scan for malware, we have found the following programs to be effective.
Microsoft Security Essentials http://www.microsoft.com/Security_Essentials/
Spybot S&D http://www.safer-networking.org/index2.html