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Bots, a sub-category of backdoor Trojans which communicate through the Internet Relay Chat (IRC) network, represent a majority of the removals. Thus, of the 5.7 million unique computers from which the tool has removed malware, a backdoor Trojan was present in 62% of computers. The MSRT has removed at least one backdoor Trojan from approximately 3.5 million unique computers. Backdoor Trojans, which can enable an attacker to control an infected computer and steal confidential information, are a significant and tangible threat to Windows users.Forty-one of the 61 malware families targeted by the MSRT from January 2005 to February 2006 have been detected less frequently since being added to the tool with 21 of the families experiencing decreases greater than 75%.On average, the tool removes at least one instance of malware from every 311 computers it runs on.
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The team also supplies the core antimalware technology (including the scanning engine and malware definition updates) to products such as Windows Live OneCare, Windows Live Safety Center Beta, Microsoft Antigen, and the upcoming Microsoft Client Security release.
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As part of this investment, Microsoft has built a dedicated Antimalware team that is responsible for researching malicious software, spyware, and other potentially unwanted software as well as the release and maintenance of the Windows Malicious Software Removal Tool (MSRT) and Windows Defender. Microsoft has made significant investments over the past few years in the research of malicious software (or “malware”) and in developing technology to help customers mitigate the security risk that it creates.
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