Signature Detail
Short Name |
SCAN:MISC:NULL |
|---|---|
Severity |
Low |
Recommended |
No |
Category |
SCAN |
Release Date |
2003/04/22 |
Update Number |
1213 |
Supported Platforms |
idp-4.0+, isg-3.0+, j-series-9.5+, mx-9.4+, srx-9.2+, srx-branch-9.4+, vsrx-12.1+ |
SCAN: Any NULL TCP Packet
This signature detects attempts to scan the system for open ports. Attackers can send NULL TCP packet (all flags turned off) to a target port and wait for a response. Open ports respond to a NULL packet with an error message; if no service is running or if no daemon is listening, the port is closed and the system responds with a RST message.
Extended Description
Port scanning is often used by hackers to determine which networks they may be able to break into.
References