Sigma
Sigma rules for CVE-2021-25032
5 rules · scoped to cve · back to CVE-2021-25032
Direct rules mention this entity in their title or description. Related rules cover the techniques this entity is known to use.
◈
Detection rules
5 of 5
direct
high
PowerShell Execution With Potential Decryption Capabilities
Detects PowerShell commands that decrypt an ".LNK" "file to drop the next stage of the malware.
view Sigma YAML
title: PowerShell Execution With Potential Decryption Capabilities
id: 434c08ba-8406-4d15-8b24-782cb071a691
status: test
description: Detects PowerShell commands that decrypt an ".LNK" "file to drop the next stage of the malware.
references:
- https://research.checkpoint.com/2023/chinese-threat-actors-targeting-europe-in-smugx-campaign/
author: X__Junior (Nextron Systems), Nasreddine Bencherchali (Nextron Systems)
date: 2023-06-30
modified: 2023-12-05
tags:
- attack.execution
logsource:
product: windows
category: process_creation
detection:
selection_img:
Image|endswith:
- '\powershell.exe'
- '\pwsh.exe'
OriginalFileName:
- 'PowerShell.EXE'
- 'pwsh.dll'
selection_cli_dir:
CommandLine|contains:
- "Get-ChildItem "
- "dir "
- "gci "
- "ls "
selection_cli_gc:
CommandLine|contains:
- "Get-Content "
- "gc "
- 'cat '
- 'type '
- 'ReadAllBytes'
selection_cli_specific:
- CommandLine|contains|all:
- ' ^| '
- '\*.lnk'
- '-Recurse'
- '-Skip '
- CommandLine|contains|all:
- ' -ExpandProperty '
- '\*.lnk'
- 'WriteAllBytes'
- ' .length '
condition: all of selection_*
falsepositives:
- Unlikely
level: high
direct
medium
PowerShell Script With File Hostname Resolving Capabilities
Detects PowerShell scripts that have capabilities to read files, loop through them and resolve DNS host entries.
view Sigma YAML
title: PowerShell Script With File Hostname Resolving Capabilities
id: fbc5e92f-3044-4e73-a5c6-1c4359b539de
status: test
description: Detects PowerShell scripts that have capabilities to read files, loop through them and resolve DNS host entries.
references:
- https://www.fortypoundhead.com/showcontent.asp?artid=24022
- https://labs.withsecure.com/publications/fin7-target-veeam-servers
author: Nasreddine Bencherchali (Nextron Systems)
date: 2023-05-05
tags:
- attack.exfiltration
- attack.t1020
logsource:
product: windows
category: ps_script
definition: bade5735-5ab0-4aa7-a642-a11be0e40872
detection:
selection:
ScriptBlockText|contains|all:
- 'Get-content '
- 'foreach'
- '[System.Net.Dns]::GetHostEntry'
- 'Out-File'
condition: selection
falsepositives:
- The same functionality can be implemented by admin scripts, correlate with name and creator
level: medium
direct
low
Capabilities Discovery - Linux
Detects usage of "getcap" binary. This is often used during recon activity to determine potential binaries that can be abused as GTFOBins or other.
view Sigma YAML
title: Capabilities Discovery - Linux
id: d8d97d51-122d-4cdd-9e2f-01b4b4933530
status: test
description: Detects usage of "getcap" binary. This is often used during recon activity to determine potential binaries that can be abused as GTFOBins or other.
references:
- https://github.com/SaiSathvik1/Linux-Privilege-Escalation-Notes
- https://github.com/carlospolop/PEASS-ng
- https://github.com/diego-treitos/linux-smart-enumeration
author: Nasreddine Bencherchali (Nextron Systems)
date: 2022-12-28
modified: 2026-01-24
tags:
- attack.discovery
- attack.t1083
logsource:
category: process_creation
product: linux
detection:
selection:
Image|endswith: '/getcap'
CommandLine|contains: ' -r '
condition: selection
falsepositives:
- Unknown
level: low
direct
low
Linux Capabilities Discovery
Detects attempts to discover the files with setuid/setgid capability on them. That would allow adversary to escalate their privileges.
view Sigma YAML
title: Linux Capabilities Discovery
id: fe10751f-1995-40a5-aaa2-c97ccb4123fe
status: test
description: Detects attempts to discover the files with setuid/setgid capability on them. That would allow adversary to escalate their privileges.
references:
- https://man7.org/linux/man-pages/man8/getcap.8.html
- https://www.hackingarticles.in/linux-privilege-escalation-using-capabilities/
- https://mn3m.info/posts/suid-vs-capabilities/
- https://int0x33.medium.com/day-44-linux-capabilities-privilege-escalation-via-openssl-with-selinux-enabled-and-enforced-74d2bec02099
author: 'Pawel Mazur'
date: 2021-11-28
modified: 2022-12-25
tags:
- attack.discovery
- attack.privilege-escalation
- attack.t1083
- attack.t1548
logsource:
product: linux
service: auditd
detection:
selection:
type: EXECVE
a0: getcap
a1: '-r'
a2: '/'
condition: selection
falsepositives:
- Unknown
level: low
direct
low
PowerShell Script With File Upload Capabilities
Detects PowerShell scripts leveraging the "Invoke-WebRequest" cmdlet to send data via either "PUT" or "POST" method.
view Sigma YAML
title: PowerShell Script With File Upload Capabilities
id: d2e3f2f6-7e09-4bf2-bc5d-90186809e7fb
status: test
description: Detects PowerShell scripts leveraging the "Invoke-WebRequest" cmdlet to send data via either "PUT" or "POST" method.
references:
- https://github.com/redcanaryco/atomic-red-team/blob/f339e7da7d05f6057fdfcdd3742bfcf365fee2a9/atomics/T1020/T1020.md
- https://www.w3.org/Protocols/rfc2616/rfc2616-sec9.html
- https://learn.microsoft.com/en-us/powershell/module/microsoft.powershell.utility/invoke-webrequest?view=powershell-7.4
author: frack113
date: 2022-01-07
modified: 2025-07-18
tags:
- attack.exfiltration
- attack.t1020
logsource:
product: windows
category: ps_script
definition: bade5735-5ab0-4aa7-a642-a11be0e40872
detection:
selection_cmdlet:
ScriptBlockText|contains:
- 'Invoke-RestMethod'
- 'Invoke-WebRequest'
- 'irm '
- 'iwr '
selection_flag:
ScriptBlockText|contains:
- '-Method "POST"'
- '-Method "PUT"'
- '-Method POST'
- '-Method PUT'
- "-Method 'POST'"
- "-Method 'PUT'"
condition: all of selection_*
falsepositives:
- Unknown
level: low
Showing 1-5 of 5