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OSSEC / HIDS Rule 5706
- Rule family: OSSEC / HIDS
- Rule ID: 5706
- Definition status: Present in current source
- Alert message / subject: SSH insecure connection attempt (scan).
- Rule level: 5
- Definition checked: 2026-10-21
Interpretation and response
This event is recorded as “SSH insecure connection attempt (scan).” Review the originating log and the affected host or service to determine whether the activity was expected.
An OSSEC/HIDS event records or correlates activity. Blocking depends on the originating application and any separately configured Active Response policy; an alert alone does not prove that an attack was blocked.
Documentation
The following guidance was migrated from the historical wiki and reviewed against the rule definition. Legacy ASL product names and interface instructions refer to the versions documented then. Use the current metadata above and your installed configuration when interpreting thresholds, notification settings and response behavior.
Description
This rule is triggered when a system connects to the sshd service but does not attempt to actually create an SSH connection. For example, if an attacker probes the port to see if SSH is running. SSH clients will not generate this alert. They create a full connection with the service, this alert will only occur if a probe against the port is initiated or if a client terminates the connection before finishing setting it up.
nmap, for example, uses this method with its version scan and will generate this alert.
Some primitive software packages will “probe” the ssh port before attempting to connect to it, instead of actually connecting. If you are using software of this type and you need to allow probes of your ssh port, you will need to disable active response for this rule.
Log example
Illustrative event summary (not a captured log): OSSEC/HIDS 5706 — SSH insecure connection attempt (scan)..
Troubleshooting
False Positives
Some simple or old monitoring packages may use this method to see if the SSH service is listening, which can generate this alert. We do not recommend you disable this rule.
Tuning Guidance
Instead if your monitoring system is generating this alert, we recommend you whitelist the IP or change to a monitoring solution that actually establishes an SSH aware connection to the SSH service.
If you do not wish to shun on this rule, just change the Rules configuration for Active Response to “no”. We do not recommend you disable active response on this rule, as this method is widely used to probe ssh servers.
Additional Information
Similar Rules
Source and revision
Migrated from HIDS_5706, wiki page 481, revision 5589 (20151027). Documentation review: 2026-10-21. An archived wiki status of Active is not a current deployment status.
For assistance, provide the rule ID, installed product and rule version, and a sanitized event to Atomicorp support .