Attack signatures in the context of network intrusion detection (especially in relation to web applications) are heuristics and data patterns that can be used to identify traffic that constitutes an attack.

For example, the regex pattern union\s+select could be used to (albeit very naively) detect SQL injection attacks. Another pattern might simply be 0x31303235343830303536, which is a value that Havij (a SQL injection tool) uses in its requests.

Signatures don't have to be related to application data. They could also be based upon packet flags, patterns of traffic (e.g. lots of unexpected DNS response packets), bad login attempts, etc.

These signatures combined can form the backbone of an Intrusion Detection System (IDS), which relies upon these patterns and heuristics in order to identify attacks and alert the administrator.

attack signatures
Have tried adding this to web.config 

&lt;compilation debug="false" targetFramework="4.0"&gt;
&lt;/compilation&gt;


but website still executes code in #if DEBUG when it shouldn't

*Wierdly the inline statement &lt;% #if DEBUG %> on aspx files works but require also for .cs code. 

NB development and live website on same box
