It indicates detection of landing page retrieval via Blackhole Exploit Kit within the network.
The Blackhole exploit kit is used to deliver a malicious payload to a victim's computer.
Any unprotected Windows system is vulnerable to the attack.
System Compromise: Remote attackers can gain control of vulnerable systems.
There is no specific vulnerability associated with this signature.
Update applications installed with the latest version.
Use Anti-Virus software to scan and clean the system.