[Snort-sigs] Bleeding addition

Brian bmc at ...95...
Mon Jun 28 10:22:03 EDT 2004


On Mon, Jun 28, 2004 at 11:38:54AM -0500, Matthew Jonkman wrote:
> What they'll do is help you find infected hosts. It's been working very 
> well for us for some time. You can generally narrow down the hosts that 
> should be sending mail to 5 or 10, these sigs will tell you where they 
> are quickly, then add them to the SMTP_SERVERS var. Lots of good info 
> will come from these. We've also caught a few vendors sending 
> 'anonymous' system information without our awareness. :)
> 
> pass tcp $SMTP_SERVERS any -> any 25 ( sid:2000324; rev: 1; 
> msg:"BLEEDING-EDGE Ignore Authorized SMTP Traffic";)
> pass tcp any any -> $SMTP_SERVERS 25 ( sid:2000325; rev: 1; 
> msg:"BLEEDING-EDGE Ignore Authorized SMTP Traffic";)
> alert tcp !$SMTP_SERVERS any -> any 25 ( sid:2000326; rev: 1; 
> msg:"BLEEDING-EDGE Possible UnAuthorized SMTP Traffic"; content:"RCPT 
> TO"; nocase;)
> 
> Again, these are in stable-side for now, they'll go into the 
> bleeding.rules in a few days.

In the process of doing this detection, you have invalidated ALL of
the SMTP rules currently in the system.  Hopefully nobody running
these rules care about attacks on their real mail servers.

Brian




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