The issue focused on Microsoft's Internet Explorer browser and Windows Vista Internet Explorer software. Google Chrome was included as well. The browsers had nearly identical malware scanners that scanned websites for potentially unwanted programs (PUPs), computer viruses, spyware and trojans. Microsoft Internet Explorer software detected malware such as Trojan horses or worms within legitimate websites more frequently than Chrome did. Microsoft Internet Explorer Software detected malware such as Trojan horses or worms within legitimate websites more frequently than Chrome did. Microsoft Computer Virus Detection Tool Software detection algorithms detect malware