Skip to content

feat: add Postfix slow brute-force and HELO rejection scenarios #1695

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Open
Etilem wants to merge 3 commits into
base: master
Choose a base branch
from
Open

feat: add Postfix slow brute-force and HELO rejection scenarios #1695

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
3 commits
Select commit Hold shift + click to select a range
4909527
feat: add Postfix slow brute-force and HELO rejection scenarios (melite)
Feb 21, 2026
5e1ed83
refactor: extend crowdsecurity/postfix-logs instead of custom parser
Etilem Mar 27, 2026
1a0f909
docs: update submission scenario to reference crowdsecurity/postfix-logs
Etilem Mar 27, 2026
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
8 changes: 8 additions & 0 deletions .tests/postfix-helo-very-slow/config.yaml
View file
Open in desktop
Original file line number Diff line number Diff line change
@@ -0,0 +1,8 @@
parsers:
- crowdsecurity/syslog-logs
- crowdsecurity/postfix-logs
- crowdsecurity/dateparse-enrich
scenarios:
- scenarios/melite/postfix-helo-very-slow.yaml
log_file: postfix-helo-very-slow.log
log_type: syslog
437 changes: 437 additions & 0 deletions .tests/postfix-helo-very-slow/parser.assert
View file
Open in desktop

Large diffs are not rendered by default.

6 changes: 6 additions & 0 deletions .tests/postfix-helo-very-slow/postfix-helo-very-slow.log
View file
Open in desktop
Original file line number Diff line number Diff line change
@@ -0,0 +1,6 @@
Jan 15 08:00:00 server postfix/smtpd[43001]: NOQUEUE: reject: RCPT from unknown[203.0.113.1]: 504 5.5.2 <invalid>: Helo command rejected: need fully-qualified hostname; from=<sender@spam.example> to=<user@example.com> proto=ESMTP helo=<invalid>
Jan 15 08:40:00 server postfix/smtpd[43002]: NOQUEUE: reject: RCPT from unknown[203.0.113.1]: 504 5.5.2 <invalid>: Helo command rejected: need fully-qualified hostname; from=<sender2@spam.example> to=<user2@example.com> proto=ESMTP helo=<invalid>
Jan 15 09:20:00 server postfix/smtpd[43003]: NOQUEUE: reject: RCPT from unknown[203.0.113.1]: 504 5.5.2 <invalid>: Helo command rejected: need fully-qualified hostname; from=<sender3@spam.example> to=<user3@example.com> proto=ESMTP helo=<invalid>
Jan 15 10:00:00 server postfix/smtpd[43004]: NOQUEUE: reject: RCPT from unknown[203.0.113.1]: 504 5.5.2 <invalid>: Helo command rejected: need fully-qualified hostname; from=<sender4@spam.example> to=<user4@example.com> proto=ESMTP helo=<invalid>
Jan 15 10:40:00 server postfix/smtpd[43005]: NOQUEUE: reject: RCPT from unknown[203.0.113.1]: 504 5.5.2 <invalid>: Helo command rejected: need fully-qualified hostname; from=<sender5@spam.example> to=<user5@example.com> proto=ESMTP helo=<invalid>
Jan 15 11:20:00 server postfix/smtpd[43006]: NOQUEUE: reject: RCPT from unknown[203.0.113.1]: 504 5.5.2 <invalid>: Helo command rejected: need fully-qualified hostname; from=<sender6@spam.example> to=<user6@example.com> proto=ESMTP helo=<invalid>
69 changes: 69 additions & 0 deletions .tests/postfix-helo-very-slow/scenario.assert
View file
Open in desktop
Original file line number Diff line number Diff line change
@@ -0,0 +1,69 @@
len(results) == 1
"203.0.113.1" in results[0].Overflow.GetSources()
results[0].Overflow.Sources["203.0.113.1"].IP == "203.0.113.1"
results[0].Overflow.Sources["203.0.113.1"].Range == ""
results[0].Overflow.Sources["203.0.113.1"].GetScope() == "Ip"
results[0].Overflow.Sources["203.0.113.1"].GetValue() == "203.0.113.1"
results[0].Overflow.Alert.Events[0].GetMeta("action") == "reject"
basename(results[0].Overflow.Alert.Events[0].GetMeta("datasource_path")) == "postfix-helo-very-slow.log"
results[0].Overflow.Alert.Events[0].GetMeta("datasource_type") == "file"
results[0].Overflow.Alert.Events[0].GetMeta("log_type") == "postfix"
results[0].Overflow.Alert.Events[0].GetMeta("machine") == "server"
results[0].Overflow.Alert.Events[0].GetMeta("reason") == "Helo command rejected: need fully-qualified hostname"
results[0].Overflow.Alert.Events[0].GetMeta("service") == "postfix"
results[0].Overflow.Alert.Events[0].GetMeta("source_hostname") == "unknown"
results[0].Overflow.Alert.Events[0].GetMeta("source_ip") == "203.0.113.1"
results[0].Overflow.Alert.Events[0].GetMeta("timestamp") == "2026-01-15T08:00:00Z"
results[0].Overflow.Alert.Events[1].GetMeta("action") == "reject"
basename(results[0].Overflow.Alert.Events[1].GetMeta("datasource_path")) == "postfix-helo-very-slow.log"
results[0].Overflow.Alert.Events[1].GetMeta("datasource_type") == "file"
results[0].Overflow.Alert.Events[1].GetMeta("log_type") == "postfix"
results[0].Overflow.Alert.Events[1].GetMeta("machine") == "server"
results[0].Overflow.Alert.Events[1].GetMeta("reason") == "Helo command rejected: need fully-qualified hostname"
results[0].Overflow.Alert.Events[1].GetMeta("service") == "postfix"
results[0].Overflow.Alert.Events[1].GetMeta("source_hostname") == "unknown"
results[0].Overflow.Alert.Events[1].GetMeta("source_ip") == "203.0.113.1"
results[0].Overflow.Alert.Events[1].GetMeta("timestamp") == "2026-01-15T08:40:00Z"
results[0].Overflow.Alert.Events[2].GetMeta("action") == "reject"
basename(results[0].Overflow.Alert.Events[2].GetMeta("datasource_path")) == "postfix-helo-very-slow.log"
results[0].Overflow.Alert.Events[2].GetMeta("datasource_type") == "file"
results[0].Overflow.Alert.Events[2].GetMeta("log_type") == "postfix"
results[0].Overflow.Alert.Events[2].GetMeta("machine") == "server"
results[0].Overflow.Alert.Events[2].GetMeta("reason") == "Helo command rejected: need fully-qualified hostname"
results[0].Overflow.Alert.Events[2].GetMeta("service") == "postfix"
results[0].Overflow.Alert.Events[2].GetMeta("source_hostname") == "unknown"
results[0].Overflow.Alert.Events[2].GetMeta("source_ip") == "203.0.113.1"
results[0].Overflow.Alert.Events[2].GetMeta("timestamp") == "2026-01-15T09:20:00Z"
results[0].Overflow.Alert.Events[3].GetMeta("action") == "reject"
basename(results[0].Overflow.Alert.Events[3].GetMeta("datasource_path")) == "postfix-helo-very-slow.log"
results[0].Overflow.Alert.Events[3].GetMeta("datasource_type") == "file"
results[0].Overflow.Alert.Events[3].GetMeta("log_type") == "postfix"
results[0].Overflow.Alert.Events[3].GetMeta("machine") == "server"
results[0].Overflow.Alert.Events[3].GetMeta("reason") == "Helo command rejected: need fully-qualified hostname"
results[0].Overflow.Alert.Events[3].GetMeta("service") == "postfix"
results[0].Overflow.Alert.Events[3].GetMeta("source_hostname") == "unknown"
results[0].Overflow.Alert.Events[3].GetMeta("source_ip") == "203.0.113.1"
results[0].Overflow.Alert.Events[3].GetMeta("timestamp") == "2026-01-15T10:00:00Z"
results[0].Overflow.Alert.Events[4].GetMeta("action") == "reject"
basename(results[0].Overflow.Alert.Events[4].GetMeta("datasource_path")) == "postfix-helo-very-slow.log"
results[0].Overflow.Alert.Events[4].GetMeta("datasource_type") == "file"
results[0].Overflow.Alert.Events[4].GetMeta("log_type") == "postfix"
results[0].Overflow.Alert.Events[4].GetMeta("machine") == "server"
results[0].Overflow.Alert.Events[4].GetMeta("reason") == "Helo command rejected: need fully-qualified hostname"
results[0].Overflow.Alert.Events[4].GetMeta("service") == "postfix"
results[0].Overflow.Alert.Events[4].GetMeta("source_hostname") == "unknown"
results[0].Overflow.Alert.Events[4].GetMeta("source_ip") == "203.0.113.1"
results[0].Overflow.Alert.Events[4].GetMeta("timestamp") == "2026-01-15T10:40:00Z"
results[0].Overflow.Alert.Events[5].GetMeta("action") == "reject"
basename(results[0].Overflow.Alert.Events[5].GetMeta("datasource_path")) == "postfix-helo-very-slow.log"
results[0].Overflow.Alert.Events[5].GetMeta("datasource_type") == "file"
results[0].Overflow.Alert.Events[5].GetMeta("log_type") == "postfix"
results[0].Overflow.Alert.Events[5].GetMeta("machine") == "server"
results[0].Overflow.Alert.Events[5].GetMeta("reason") == "Helo command rejected: need fully-qualified hostname"
results[0].Overflow.Alert.Events[5].GetMeta("service") == "postfix"
results[0].Overflow.Alert.Events[5].GetMeta("source_hostname") == "unknown"
results[0].Overflow.Alert.Events[5].GetMeta("source_ip") == "203.0.113.1"
results[0].Overflow.Alert.Events[5].GetMeta("timestamp") == "2026-01-15T11:20:00Z"
results[0].Overflow.Alert.GetScenario() == "melite/postfix-helo-very-slow"
results[0].Overflow.Alert.Remediation == true
results[0].Overflow.Alert.GetEventsCount() == 6
8 changes: 8 additions & 0 deletions .tests/postfix-slow-bf/config.yaml
View file
Open in desktop
Original file line number Diff line number Diff line change
@@ -0,0 +1,8 @@
parsers:
- crowdsecurity/syslog-logs
- crowdsecurity/postfix-logs
- crowdsecurity/dateparse-enrich
scenarios:
- scenarios/melite/postfix-slow-bf.yaml
log_file: postfix-slow-bf.log
log_type: syslog
Loading