PestPatrol is regular corrupt anti-spyware, but it's more dangerous than most of it competitors. Pest Patrol is fraudulent application, but there is a genuine one named eTrust Pestpatrol. The eTrust Pestpatrol is quite reputable and known among computer owners and some of them may take the malicious PestPatrol as legitimate one.
If you hadn't installed eTrust PestPatrol and you see pop-ups supposedly related to this software, don't trust them and don't pay for the services. Remove Pest Patrol without hesitation.