# RouterOS Suricata TZSP - built-in rules.
#
# SID 1000001 is reserved for the deterministic pipeline self-test. It only
# matches the marker emitted by scripts/send_test_tzsp.py, so normal ICMP/ping
# traffic cannot trigger it. The application also ignores this SID in the
# incident database by default.
alert icmp any any -> any any (msg:"LOCAL TEST TZSP PIPELINE MARKER"; itype:8; content:"routeros-suricata-tzsp-selftest"; nocase; classtype:misc-activity; priority:3; sid:1000001; rev:3;)

# Conservative production baseline. ET/Open is baked into the image as the
# vendor ruleset; these local rules add a few rate-based detections that are
# useful on a mirrored RouterOS edge without alerting on single packets.

# Repeated external SSH connection attempts against HOME_NET.
alert tcp $EXTERNAL_NET any -> $HOME_NET 22 (msg:"LOCAL PROD repeated SSH connection attempts"; flags:S; flow:stateless; threshold: type both, track by_src, count 10, seconds 60; classtype:attempted-admin; priority:1; sid:1000101; rev:1;)

# Repeated external RDP connection attempts against HOME_NET.
alert tcp $EXTERNAL_NET any -> $HOME_NET 3389 (msg:"LOCAL PROD repeated RDP connection attempts"; flags:S; flow:stateless; threshold: type both, track by_src, count 8, seconds 60; classtype:attempted-admin; priority:1; sid:1000102; rev:1;)

# Repeated access attempts to RouterOS WinBox from outside HOME_NET.
alert tcp $EXTERNAL_NET any -> $HOME_NET 8291 (msg:"LOCAL PROD repeated RouterOS WinBox connection attempts"; flags:S; flow:stateless; threshold: type both, track by_src, count 8, seconds 60; classtype:attempted-admin; priority:1; sid:1000103; rev:1;)

# High-rate SYN activity against HOME_NET. The threshold intentionally requires
# a burst to avoid treating ordinary connection setup as a scan.
alert tcp $EXTERNAL_NET any -> $HOME_NET any (msg:"LOCAL PROD possible TCP SYN scan"; flags:S; flow:stateless; threshold: type both, track by_src, count 40, seconds 10; classtype:attempted-recon; priority:2; sid:1000104; rev:1;)

# High-rate ICMP echo requests from one external source.
alert icmp $EXTERNAL_NET any -> $HOME_NET any (msg:"LOCAL PROD possible ICMP sweep"; itype:8; threshold: type both, track by_src, count 20, seconds 10; classtype:attempted-recon; priority:2; sid:1000105; rev:1;)

# Direct inbound SMB from outside HOME_NET. Rate-limited because some networks
# intentionally expose SMB over controlled tunnels or provider networks.
alert tcp $EXTERNAL_NET any -> $HOME_NET [139,445] (msg:"LOCAL PROD inbound SMB from external network"; flags:S; flow:stateless; threshold: type limit, track by_src, count 1, seconds 300; classtype:policy-violation; priority:2; sid:1000106; rev:1;)

# Very long first DNS labels can be a tunnelling/exfiltration signal. A single
# source can create at most one alert every five minutes for this local rule.
alert dns $HOME_NET any -> any 53 (msg:"LOCAL PROD unusually long DNS query label"; dns.query; pcre:"/^[A-Za-z0-9_-]{48,}\./"; threshold: type limit, track by_src, count 1, seconds 300; classtype:bad-unknown; priority:2; sid:1000107; rev:1;)

# Cleartext Telnet leaving HOME_NET. One alert per source every ten minutes.
alert tcp $HOME_NET any -> $EXTERNAL_NET 23 (msg:"LOCAL PROD outbound Telnet session"; flow:established,to_server; threshold: type limit, track by_src, count 1, seconds 600; classtype:policy-violation; priority:2; sid:1000108; rev:1;)

# Repeated NXDOMAIN replies to a HOME_NET client. This can indicate DGA-style
# beaconing, typo storms or broken/malicious name generation. The threshold is
# intentionally high enough to avoid alerting on isolated failed lookups.
alert dns any any -> $HOME_NET any (msg:"LOCAL PROD repeated DNS NXDOMAIN responses"; dns.rcode:NXDOMAIN; threshold: type both, track by_dst, count 30, seconds 60; classtype:bad-unknown; priority:2; sid:1000109; rev:1;)

# High-rate DNS queries from one HOME_NET source. Combined with the long-label
# rule this adds a rate signal for tunnelling, DGA and resolver abuse.
alert dns $HOME_NET any -> any 53 (msg:"LOCAL PROD high-rate DNS query activity"; dns.query; pcre:"/.+/"; threshold: type both, track by_src, count 120, seconds 60; classtype:bad-unknown; priority:2; sid:1000110; rev:1;)

# SMB should normally stay inside trusted networks or explicit tunnels. Direct
# Internet SMB is a strong policy signal and is rate-limited per source.
alert tcp $HOME_NET any -> $EXTERNAL_NET 445 (msg:"LOCAL PROD outbound SMB to external network"; flags:S; flow:stateless; threshold: type limit, track by_src, count 1, seconds 600; classtype:policy-violation; priority:1; sid:1000111; rev:1;)

# Direct SMTP from endpoints is frequently associated with compromised hosts.
# Mail relays can suppress this SID or scope it with threshold.config.
alert tcp $HOME_NET any -> $EXTERNAL_NET 25 (msg:"LOCAL PROD direct outbound SMTP"; flags:S; flow:stateless; threshold: type limit, track by_src, count 1, seconds 600; classtype:policy-violation; priority:2; sid:1000112; rev:1;)

# Cleartext FTP leaving HOME_NET. Kept as a policy alert rather than an automatic
# block because legacy infrastructure may still require it.
alert tcp $HOME_NET any -> $EXTERNAL_NET 21 (msg:"LOCAL PROD outbound cleartext FTP"; flags:S; flow:to_server,stateless; threshold: type limit, track by_src, count 1, seconds 600; classtype:policy-violation; priority:2; sid:1000113; rev:2;)

# Common database/search service ports should not normally be reachable directly
# from the Internet. This detects exposure/probing without alerting on every SYN.
alert tcp $EXTERNAL_NET any -> $HOME_NET [3306,5432,6379,9200,27017] (msg:"LOCAL PROD external access to database service"; flags:S; flow:stateless; threshold: type limit, track by_src, count 1, seconds 300; classtype:attempted-admin; priority:1; sid:1000114; rev:1;)

# Burst of administrative/lateral-movement connection attempts inside HOME_NET.
# Normal single RDP/SMB sessions do not trigger this rule.
alert tcp $HOME_NET any -> $HOME_NET [445,3389] (msg:"LOCAL PROD possible internal lateral movement burst"; flags:S; flow:stateless; threshold: type both, track by_src, count 40, seconds 30; classtype:attempted-admin; priority:1; sid:1000115; rev:1;)

# Multi-stage state tracking with Suricata 8 xbits. A scan burst marks the
# source for ten minutes; a later hit on an administrative service becomes a
# higher-confidence correlated alert instead of treating both events in isolation.
alert tcp $EXTERNAL_NET any -> $HOME_NET any (msg:"LOCAL NDR mark external scanner"; flags:S; flow:stateless; threshold: type threshold, track by_src, count 30, seconds 10; xbits:set,ms_ext_scanner,track ip_src,expire 600; noalert; sid:1000120; rev:1;)
alert tcp $EXTERNAL_NET any -> $HOME_NET [22,445,3389,8291] (msg:"LOCAL NDR scan followed by administrative service access"; flags:S; flow:stateless; xbits:isset,ms_ext_scanner,track ip_src; threshold: type limit, track by_src, count 1, seconds 300; classtype:attempted-admin; priority:1; sid:1000121; rev:1;)

# The same idea for east-west traffic. This is deliberately burst-based so a
# normal single SMB/RDP/SSH connection does not mark a workstation.
alert tcp $HOME_NET any -> $HOME_NET any (msg:"LOCAL NDR mark internal lateral probe"; flags:S; flow:stateless; threshold: type threshold, track by_src, count 35, seconds 20; xbits:set,ms_lateral_probe,track ip_src,expire 900; noalert; sid:1000122; rev:1;)
alert tcp $HOME_NET any -> $HOME_NET [22,445,3389,5985,5986,8291] (msg:"LOCAL NDR lateral probe followed by administrative access"; flags:S; flow:stateless; xbits:isset,ms_lateral_probe,track ip_src; threshold: type limit, track by_src, count 1, seconds 300; classtype:attempted-admin; priority:1; sid:1000123; rev:1;)


# RouterOS API/API-SSL should normally be restricted to trusted administration
# networks. Repeated Internet connection attempts are a MikroTik-specific
# management-plane signal similar to WinBox probing.
alert tcp $EXTERNAL_NET any -> $HOME_NET [8728,8729] (msg:"LOCAL PROD repeated RouterOS API connection attempts"; flags:S; flow:stateless; threshold: type both, track by_src, count 8, seconds 60; classtype:attempted-admin; priority:1; sid:1000116; rev:1;)