I-rule for adapt request "response page"

Hi Wasfi_Bounni , 
I think irules in the below links may help you: 
Niels_van_Sluis's one 
https://community.f5.com/t5/technical-forum/icap-with-irule-response-page-without-asm/td-p/221613

If it doesn't work with you , use this even (when ICAP_RESPONSE)
instead of when ADAPT_REQUEST_RESULT

and use if condition , to match on any string or data coming from ICAP server after Virus detected.

Or Navigate this discussion as well : 
https://community.f5.com/t5/technical-forum/is-it-possible-to-insert-http-payload-in-an-icap-reply-or-to/td-p/299959

Like these irules much tricky ‌‌😃