alert ip any any -> $HOME_NET $SIP_PROXY_PORTS (msg:"OPTIONS SIP scan"; content:"OPTIONS"; depth:7; threshold: type both , track by_src, count 30, seconds 3; sid:5000001; rev:1;)
# Excessive number of SIP 4xx Responses Does not work
#### alert ip any any -> $SIP_PROXY_IP $SIP_PROXY_PORTS (msg:"Excessive number of SIP 4xx Responses - possible user or password guessing attack"; pcre:"/^SIP\/2.0 4\d{2}"; threshold: type both, track by_src, count 100, seconds 60; sid:5000002; rev:1;)
alert ip any any -> $SIP_PROXY_IP $SIP_PROXY_PORTS (msg:"Ghost call attack"; content:"SIP/2.0 180"; depth:11; threshold: type both, track by_src, count 100, seconds 60; sid:5000003; rev:1;)
# Rule for alerting of INVITE flood attack:
alert ip any any -> $SIP_PROXY_IP $SIP_PROXY_PORTS (msg:"INVITE message flooding"; content:"INVITE"; depth:6; threshold: type both , track by_src, count 100, seconds 60; sid:5000004; rev:1;)
# Rule for alerting of REGISTER flood attack:
alert ip any any -> $SIP_PROXY_IP $SIP_PROXY_PORTS (msg:"REGISTER message flooding"; content:"REGISTER"; depth:8; threshold: type both , track by_src, count 100, seconds 60; sid:5000005; rev:1;)
# Threshold rule for unauthorized responses:
alert ip any any -> $SIP_PROXY_IP $SIP_PROXY_PORTS (msg:"INVITE message flooding"; content:"SIP/2.0 401 Unauthorized"; depth:24; threshold: type both, track by_src, count 100, seconds 60; sid:5000006; rev:1;)