If you apply Q312461 (MS01-055) patch to your IE 5.5 SP2 / 6, your IE shows patch information into HTTP_USER_AGENT as: IE 6: Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.0; Q312461) IE 5.5 SP2: Mozilla/4.0 (compatible; MSIE 5.5; Windows NT 5.0; T312461) You can find vulnerable IE 5.5/6 very easily... What's this? ------------ It's registry entry, at: HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Internet Settings\User Agent\Post Platform Tested ------ * Windows 2000 SP2 (japanese) + IE 5.5 SP2 (japanese) + Q312461 (japanese) * Windows 2000 SP2 (japanese) + IE 6 (japanese) + Q312461 (japanese) 1st reported by --------------- SUZUKI, Kazuhiro http://memo.st.ryukoku.ac.jp/archive/200111.month/1890.html (caution: this URL is written in Japanese) ---- KOJIMA Hajime - Ryukoku University, Seta, Ootsu, Shiga, 520-2194 Japan [Office] kjm@rins.ryukoku.ac.jp, http://www.st.ryukoku.ac.jp/~kjm/