msdt.exe - Trojan W32.Tilebot-BQ
[A quick search of the issue yielded this result]
Combofix 'should have gotten it', but; you can try the Sophos tool:
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W32/Tilebot-BQ is a worm and IRC backdoor Trojan for the Windows platform.
W32/Tilebot-BQ spreads to other network computers by exploiting common buffer overflow vulnerabilities, including: PNP (MS05-039), ASN.1 (MS04-007), and RPC-DCOM (MS04-012), and by copying itself to network shares and Microsoft SQL servers protected by weak passwords.
W32/Tilebot-BQ runs continuously in the background, providing a backdoor server which allows a remote intruder to gain access and control over the computer via IRC channels.
W32/Tilebot-BQ includes functionality to access the internet and communicate with a remote server via HTTP.
When first run W32/Tilebot-BQ copies itself to <Windows>\msdt.exe.
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hth