(imported comment written by SLB)
I realize this is an oldish thread but I’ve recently been trying to see if I can find the defination date of a Forefront client and saw this thread so I thought I’d let people know what I found out. If you want to check if a client has recent Forefront definitions, you can do this by querying the local registry of a machine as MS write the date of the Forefront definition into the registry. Its takes a bit of mathematics to get to the date as the reg value is a reg_binary value represent the number of nano seconds that have elapsed since Jan 1st 1601 00:00:00. The conversion is, decimal value of the 1st octect + decimal value of the 2nd octect multipled by 2^8 + decimal value of the 3rd octect multipled by 2^16 + decimal value of the 4th octect multipled by 2^24 + decimal value of the 5th octect multipled by 2^32 + decimal value of the 6th octect multipled by 2^40 + decimal value of the 7th octect multipled by 2^48 + decimal value of the 8th octect multipled by 2^56 then divide by 10000000. This give you the total number of seconds elapsed since Jan 1st 1601 00:00:00 which you can add to get the defination date. In relevance terms this is
((((hexadecimal integer (first 2 of it))+(hexadecimal integer (first 2 of last 14 of it) * 256)+(hexadecimal integer (first 2 of last 12 of it) * 65536)+(hexadecimal integer (first 2 of last 10 of it) * 16777216)+(hexadecimal integer (first 2 of last 8 of it) * 4294967296)+(hexadecimal integer (first 2 of last 6 of it) * 1099511627776)+(hexadecimal integer (first 2 of last 4 of it) * 281474976710656)+(hexadecimal integer (last 2 of it) * 72057594037927900)) /10000000 ) of (value “AVSignatureApplied” of key “HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Microsoft Forefront\Client Security\1.0\AM\Signature Updates” of native registry as string)) * second + “01 Jan 1601 00:00:00” as universal time
Hope this is of use to some of you.
Rob