This detection is not a detection for the vulnerability of your machine. If you got this warning, it is an indication that a malicious piece of code passed through your network or your machine, but was detected by Trend Micro as MS04-007_ASN_EXPLOIT.
If you have patched your system against the Microsoft ASN Vulnerability, then your system should be safe from the damage that may be brought about by this exploit code.
Otherwise, you can look up the patch information for your Windows version on this site. Trend Micro advises users to refrain from using their system until it has been completely patched against this vulnerability.
Trend Micro Solution
Users of Trend Micro PC-cillin Internet Security and Network VirusWall can detect this exploit at the network layer with Network Virus Pattern (NVP) 10115, or later.
Disabling Network Virus Emergency Center Pop-ups
If you have already patched your system, and want to turn the pop-up messages off, please refer to the following Knowledge Base solutions:
Note: Disabling the network virus pop-up display option means you will not be alerted for ALL network attacks to your system, not just this particular exploit attack.