Many Windows PC systems have been turned into “zombie” machines by hackers, while rootkits have not spread as significantly.
Microsoft has reported that over 60% of Windows PC systems have been found to be infected with malicious “bot” software when scanned with the Windows Malicious Software Removal Tool. This Microsoft tool has removed at least one version of remote control software from approximately 3.5 million PCs.
“Backdoor Trojans are a tangible threat to users of Windows PC systems,” Microsoft asserts.
Infected PCs, commonly referred to as “zombie PCs,” can be used to build “bot” systems, also known as “botnets,” for sending spam or launching attacks. Furthermore, hackers can steal information from these “zombie PCs” or install spyware and adware to profit from those who develop such software.
Microsoft officially launched the Windows Malicious Software Removal Tool last year. The software is updated monthly alongside security updates, aiming to identify and remove any malware from users’ systems. Since its launch, the tool has been run approximately 2.7 billion times on 270 million systems.
In over 15 months of operation, this tool has discovered a total of 5.7 million Windows operating systems infected with malware and removed 16 million pieces of malware from these systems.
Backdoor Trojans are the most common threat, followed by email-spreading worms—statistics show this type of security threat has been detected on over 1 million PC systems. Meanwhile, rootkits have only been detected and removed from 780,000 PC systems.
Rootkits are a potential security threat that is emerging but has not yet achieved wide prevalence, Microsoft concludes. This is completely contrary to a study by security company McAfee last April, which asserted that the number of rootkits is increasing significantly.
The Windows Malicious Software Removal Tool has only detected rootkits in 14% of the 5.7 million infected PC systems. Additionally, about 20% of rootkit infections also coincide with backdoor Trojan infections.
The top five security threats identified by Microsoft are bot, Sdbot, Parite, Gaobot, and FURootkit.
Hoàng Dũng
