> 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/an-uncommon-executable-was-remotely-written-over-smb-to-an-uncommon-destination.md).
# An uncommon executable was remotely written over SMB to an uncommon destination
### 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) |
| ATT\&CK Tactic | Lateral Movement (TA0008) |
| ATT\&CK Technique | Remote Services: SMB/Windows Admin Shares (T1021.002) |
| Severity | Low |
### Description
An uncommon executable was remotely written over SMB to a destination, which was not involved in significant similar activity during last month.
### Attacker's Goals
Transfer tools as part of lateral movement activity across the network.
### Investigative actions
* Verify if the shared file is malicious.
* Investigate if the file was executed on the host.
* Check the remote SMB client for other suspicious activities.
### Variations
An uncommon executable was remotely written over SMB to a highly suspicious destination
**Synopsis**
| Field | Value |
| ----------------- | ----------------------------------------------------- |
| ATT\&CK Tactic | Lateral Movement (TA0008) |
| ATT\&CK Technique | Remote Services: SMB/Windows Admin Shares (T1021.002) |
| Severity | High |
**Description**
An uncommon executable was remotely written over SMB to a highly suspicious destination, which was not involved in significant similar activity during last month.
**Attacker's Goals**
Transfer tools as part of lateral movement activity across the network.
**Investigative actions**
* Verify if the shared file is malicious.
* Investigate if the file was executed on the host.
* Check the remote SMB client for other suspicious activities.
An uncommon executable with SCR extension was remotely written over SMB to an uncommon destination
**Synopsis**
| Field | Value |
| ----------------- | ----------------------------------------------------- |
| ATT\&CK Tactic | Lateral Movement (TA0008) |
| ATT\&CK Technique | Remote Services: SMB/Windows Admin Shares (T1021.002) |
| Severity | Medium |
**Description**
An uncommon executable with SCR extension was remotely written over SMB to a destination, which was not involved in significant similar activity during last month.
**Attacker's Goals**
Transfer tools as part of lateral movement activity across the network, leveraging lesser known PE extension to masquerade a malicious file.
**Investigative actions**
* Verify if the shared file is malicious.
* Investigate if the file was executed on the host.
* Check the remote SMB client for other suspicious activities.
* Verify whether or not the executable file is a genuine screensaver, possibly by detonating it in a controlled environment.
PsExec remote service component was remotely written over SMB to an uncommon destination
**Synopsis**
| Field | Value |
| ----------------- | ----------------------------------------------------- |
| ATT\&CK Tactic | Lateral Movement (TA0008) |
| ATT\&CK Technique | Remote Services: SMB/Windows Admin Shares (T1021.002) |
| Severity | Low |
**Description**
PsExec remote service component was remotely written over SMB to a destination, which was not involved in significant similar activity during last month.
**Attacker's Goals**
Transfer tools as part of lateral movement activity across the network.
**Investigative actions**
* Verify if the shared file is malicious.
* Investigate if the file was executed on the host.
* Check the remote SMB client for other suspicious activities.
* Verify whether this is part of authorized activity or not as PsExec can be used for both benign and malicious purposes.
---
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