# Sagan imapd*.rules
# Copyright (c) 2009-2020. Quadrant Information Security <www.quadrantsec.com>
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#
# Please submit any custom rules or ideas to sagan-submit@quadrantsec.com or the sagan-sigs mailing list
#
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#*************************************************************

alert any $EXTERNAL_NET any -> $HOME_NET any (msg: "[IMAPD] User login failed"; pcre: "/Login failed user=|AUTHENTICATE LOGIN failure/i"; default_proto: tcp; default_dst_port: $IMAP_PORT; classtype: unsuccessful-user; parse_src_ip: 1; program: imapd*; reference: url,wiki.quadrantsec.com/bin/view/Main/5000367; sid: 5000367; rev:7;)
alert any $EXTERNAL_NET any -> $HOME_NET any (msg: "[IMAPD] Successful login"; content: "Authenticated user="; default_proto: tcp; default_dst_port: $IMAP_PORT; classtype: successful-user; program: imapd*; parse_src_ip: 1; reference: url,wiki.quadrantsec.com/bin/view/Main/5000262; sid: 5000262; rev:6;)
alert any $EXTERNAL_NET any -> $HOME_NET any (msg: "[IMAPD] User logout"; content: "Logout user="; default_proto: tcp; default_dst_port: $IMAP_PORT; classtype: not-suspicious; program: imapd*; normalize; reference: url,wiki.quadrantsec.com/bin/view/Main/5000276; sid:5000276; rev:5;)
alert any $EXTERNAL_NET any -> $HOME_NET any (msg: "[IMAPD] Exessive login failures"; content: "Login excessive login"; default_proto: tcp; default_dst_port: $IMAP_PORT; classtype: unsuccessful-user; program: imapd*; normalize; parse_src_ip: 1; xbits: set,brute_force,track ip_src, expire 21600; reference: url,wiki.quadrantsec.com/bin/view/Main/5001078; sid: 5001078; rev:8;)
alert any $EXTERNAL_NET any -> $HOME_NET any (msg: "[IMAPD] Brute force attack [5/1]"; pcre: "/Login failed user=|AUTHENTICATE LOGIN failure/i"; default_proto: tcp; default_dst_port: $IMAP_PORT; classtype: unsuccessful-user; parse_src_ip: 1; xbits: set,brute_force,track ip_src, expire 21600; after: track by_src, count 5, seconds 300; threshold: type suppress, track by_src, count 1, seconds 300; program: imapd*; reference: url,wiki.quadrantsec.com/bin/view/Main/5002947; sid:5002947; rev:3;)