HIDS 9952
| Rule 9952 | |
|---|---|
| Status | Active |
| Alert Message | Vpopmail brute force (email harvesting). |
Contents |
[edit] Description
ASL has detected multiple failed attempts to access a vpopmail user account that does not exist. This generally indicates that an attacker is try to find user accounts to hack into. This rule specifically looks for 8 failed attempts in 240 seconds.
[edit] Troubleshooting
[edit] Solutions
We do not recommend you disable this rule. You could whitelist the IP, but the best solution is to fix the invalid username for the user.
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 brute force mail accounts or to find email addresses to spam.
[edit] False Positives
The rule itself can not generate a false positive, the rule just reports when multiple login failures happen from a single IP. If this event is not an attack, then this means the enduser has an invalid username configured for the service. The best solution to this problem is to have the user fix their username so its valid.
Please do not report this as a false positive unless ASL is incorrectly reporting an event that is not a login failure for your mail server. To report a false positive, please follow this process:
https://www.atomicorp.com/wiki/index.php/Reporting_False_Positives
[edit] Additional Information
[edit] Similar Rules
[edit] Knowledge Base Articles
None.
[edit] External Articles
None.
