• Status: Solved
  • Priority: Medium
  • Security: Public
  • Views: 1088
  • Last Modified:

question regarding snort rule

Hi,
I am somewhat new to reading snort rule sets.  Can someone translate this for me.  Thanks.


alert tcp $HOME_NET any -> $EXTERNAL_NET $HTTP_PORTS (msg:"ET MALWARE Sogoul.com Spyware User-Agent (SogouIMEMiniSetup?)"; flow:established,to_server; content:"User-Agent|3a| SogouIME?"; http_header; reference:url,doc.emergingthreats.net/2008500; classtype:trojan-activity; sid:2008500; rev:6;)
0
NYGiantsFan
Asked:
NYGiantsFan
1 Solution
 
Rich RumbleSecurity SamuraiCommented:
Alert when a TCP connection from your network connects to an external network on http ports (typically just 80), and when the flow that is established contains the words "User-Agent: SogouIME?".

3a is a colon, that's why they have plain-text mixed with hex (and that's why there are pipe characters in the rule) is so snort and or suricata don't interpret the colon as a rule delimiter. |3a| just means colon, it's an easy escape sequence for that rule, but it's not the only way to do it.
http://doc.emergingthreats.net/2011176
Read down toward the bttom of the references to see what notes might (or might not) be present about the rules.
-rich
0

Featured Post

Keep up with what's happening at Experts Exchange!

Sign up to receive Decoded, a new monthly digest with product updates, feature release info, continuing education opportunities, and more.

Tackle projects and never again get stuck behind a technical roadblock.
Join Now