> For the complete documentation index, see [llms.txt](https://cortex-docs.paloaltonetworks.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://cortex-docs.paloaltonetworks.com/analytics-alerts/alerts-by-name/unusual-certlog-remote-file-write.md).
# Unusual CertLog Remote File Write
### Synopsis
| Field | Value |
| -------------------- | -------------------------------------------------- |
| Activation Period | 14 Days |
| Training Period | 30 Days |
| Test Period | N/A (single event) |
| Deduplication Period | 1 Day |
| Required Data | XDR Agent with eXtended Threat Hunting (XTH) |
| Detection Modules | Identity Analytics |
| Detector Tags | Active Directory Certificate Services Analytics |
| ATT\&CK Tactic | Credential Access (TA0006) |
| ATT\&CK Technique | Steal or Forge Authentication Certificates (T1649) |
| Severity | Low |
### Description
A remote host wrote to a certificate log file via RPC over SMB, which may indicate the use of an AD CS attack tool like Certipy. This behavior is commonly associated with certificate-based authentication attacks.
### Attacker's Goals
An attacker may be attempting to exploit AD CS misconfigurations and obtain forged authentication certificates for privilege escalation or persistence.
### Investigative actions
* Determine whether this was a legitimate certificate request or an unauthorized write operation.
* Review logs for preceding and subsequent authentication attempts.
* Investigate the remote host for any suspicious activity.
* Identify any subsequent Kerberos ticket usage, such as forging or relaying attacks.
### Variations
Suspicious CertLog Remote File Write
**Synopsis**
| Field | Value |
| ----------------- | -------------------------------------------------- |
| ATT\&CK Tactic | Credential Access (TA0006) |
| ATT\&CK Technique | Steal or Forge Authentication Certificates (T1649) |
| Severity | Medium |
**Description**
A remote host wrote to a certificate log file via RPC over SMB, which may indicate the use of an AD CS attack tool like Certipy. This behavior is commonly associated with certificate-based authentication attacks.
**Attacker's Goals**
An attacker may be attempting to exploit AD CS misconfigurations and obtain forged authentication certificates for privilege escalation or persistence.
**Investigative actions**
* Determine whether this was a legitimate certificate request or an unauthorized write operation.
* Review logs for preceding and subsequent authentication attempts.
* Investigate the remote host for any suspicious activity.
* Identify any subsequent Kerberos ticket usage, such as forging or relaying attacks.
---
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