DOS attack from AS

Once in a while (maybe once a month), our intranet is a victim of what I would call a DOS. Our application server (AS 10.1.2.2) receives hundreds of requests (all the same request with the same parameters) from the a user in a few minutes for a modplsql application. It's impossible for a person to send so much requests in that period of time. It floods the db (10.2.0.3) and everyone hangs.

Each time, it's a different user. Our PC experts scanned the PCs with a variety of antivirus and anti-spyware but found nothing suspicious. Anyone else have experienced something like that ?

Louis Brouillette
Analyste en informatique (DBA)
Universite du Quebec a Trois-Rivieres
Tel: (819) 376-5011 ext. 2435
Email: brouille_at_uqtr.ca

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