Sigma is the open generic signature format for SIEM systems. Each rule below converts to native syntax for Splunk, Elastic, Sentinel, and other SIEMs. Expand any rule to see its raw YAML.
Detects Silence EmpireDNSAgent as described in the Group-IP report
status testauthor Alina Stepchenkova, Group-IB, oscd.communityid 3ceb2083-a27f-449a-be33-14ec1b7cc973
view Sigma YAML
title: Silence.EDA Detection
id: 3ceb2083-a27f-449a-be33-14ec1b7cc973
status: test
description: Detects Silence EmpireDNSAgent as described in the Group-IP report
references:
- https://www.group-ib.com/resources/threat-research/silence_2.0.going_global.pdf
author: Alina Stepchenkova, Group-IB, oscd.community
date: 2019-11-01
modified: 2023-04-03
tags:
- attack.execution
- attack.t1059.001
- attack.command-and-control
- attack.t1071.004
- attack.t1572
- attack.impact
- attack.t1529
- attack.g0091
- attack.s0363
logsource:
product: windows
category: ps_script
definition: 'Requirements: Script Block Logging must be enabled'
detection:
empire:
# better to randomise the order
ScriptBlockText|contains|all:
- 'System.Diagnostics.Process'
- 'Stop-Computer'
- 'Restart-Computer'
- 'Exception in execution'
- '$cmdargs'
- 'Close-Dnscat2Tunnel'
dnscat:
# better to randomise the order
ScriptBlockText|contains|all:
- 'set type=$LookupType`nserver'
- '$Command | nslookup 2>&1 | Out-String'
- 'New-RandomDNSField'
- '[Convert]::ToString($SYNOptions, 16)'
- '$Session.Dead = $True'
- '$Session["Driver"] -eq'
condition: empire and dnscat
falsepositives:
- Unknown
level: critical
medium
Cisco Denial of Service
Detect a system being shutdown or put into different boot mode
status testauthor Austin Clarkid d94a35f0-7a29-45f6-90a0-80df6159967c
view Sigma YAML
title: Cisco Denial of Service
id: d94a35f0-7a29-45f6-90a0-80df6159967c
status: test
description: Detect a system being shutdown or put into different boot mode
author: Austin Clark
date: 2019-08-15
modified: 2023-01-04
tags:
- attack.impact
- attack.t1495
- attack.t1529
- attack.t1565.001
logsource:
product: cisco
service: aaa
detection:
keywords:
- 'shutdown'
- 'config-register 0x2100'
- 'config-register 0x2142'
condition: keywords
falsepositives:
- Legitimate administrators may run these commands, though rarely.
level: medium
medium
ESXi VM Kill Via ESXCLI
Detects execution of the "esxcli" command with the "vm" and "kill" flag in order to kill/shutdown a specific VM.
status testauthor Nasreddine Bencherchali (Nextron Systems), Cedric Maurugeonid 2992ac4d-31e9-4325-99f2-b18a73221bb2
view Sigma YAML
title: ESXi VM Kill Via ESXCLI
id: 2992ac4d-31e9-4325-99f2-b18a73221bb2
status: test
description: Detects execution of the "esxcli" command with the "vm" and "kill" flag in order to kill/shutdown a specific VM.
references:
- https://www.crowdstrike.com/blog/hypervisor-jackpotting-ecrime-actors-increase-targeting-of-esxi-servers/
- https://developer.broadcom.com/xapis/esxcli-command-reference/7.0.0/namespace/esxcli_vm.html
- https://www.secuinfra.com/en/techtalk/hide-your-hypervisor-analysis-of-esxiargs-ransomware/
- https://www.trendmicro.com/en_us/research/22/e/new-linux-based-ransomware-cheerscrypt-targets-exsi-devices.html
author: Nasreddine Bencherchali (Nextron Systems), Cedric Maurugeon
date: 2023-09-04
tags:
- attack.execution
- attack.impact
- attack.t1059.012
- attack.t1529
logsource:
category: process_creation
product: linux
detection:
selection:
Image|endswith: '/esxcli'
CommandLine|contains|all:
- 'vm process'
- 'kill'
condition: selection
falsepositives:
- Legitimate administration activities
level: medium
medium
Potential Abuse of Linux Magic System Request Key
Detects the potential abuse of the Linux Magic SysRq (System Request) key by adversaries with root or sufficient privileges
to silently manipulate or destabilize a system. By writing to /proc/sysrq-trigger, they can crash the system, kill processes,
or disrupt forensic analysis—all while bypassing standard logging. Though intended for recovery and debugging, SysRq can be
misused as a stealthy post-exploitation tool. It is controlled via /proc/sys/kernel/sysrq or permanently through /etc/sysctl.conf.
status experimentalauthor Milad Cheraghiid ea61bb82-a5e0-42e6-8537-91d29500f1b9
view Sigma YAML
title: Potential Abuse of Linux Magic System Request Key
id: ea61bb82-a5e0-42e6-8537-91d29500f1b9
status: experimental
description: |
Detects the potential abuse of the Linux Magic SysRq (System Request) key by adversaries with root or sufficient privileges
to silently manipulate or destabilize a system. By writing to /proc/sysrq-trigger, they can crash the system, kill processes,
or disrupt forensic analysis—all while bypassing standard logging. Though intended for recovery and debugging, SysRq can be
misused as a stealthy post-exploitation tool. It is controlled via /proc/sys/kernel/sysrq or permanently through /etc/sysctl.conf.
references:
- https://www.kernel.org/doc/html/v4.10/_sources/admin-guide/sysrq.txt
- https://docs.redhat.com/en/documentation/red_hat_enterprise_linux/4/html/reference_guide/s3-proc-sys-kernel
- https://www.splunk.com/en_us/blog/security/threat-update-awfulshred-script-wiper.html
author: Milad Cheraghi
date: 2025-05-23
tags:
- attack.execution
- attack.t1059.004
- attack.impact
- attack.t1529
- attack.t1489
- attack.t1499
logsource:
product: linux
service: auditd
definition: |
Required auditd configuration:
-w /proc/sysrq-trigger -p wa -k sysrq
-w /proc/sys/kernel/sysrq -p wa -k sysrq
detection:
selection:
type: 'PATH'
name|endswith:
# Enable
- '/sysrq'
- '/sysctl.conf'
# Execute
- '/sysrq-trigger'
condition: selection
falsepositives:
- Legitimate administrative activity
level: medium
medium
Suspicious Execution of Shutdown
Use of the commandline to shutdown or reboot windows
status testauthor frack113id 34ebb878-1b15-4895-b352-ca2eeb99b274
view Sigma YAML
title: Suspicious Execution of Shutdown
id: 34ebb878-1b15-4895-b352-ca2eeb99b274
status: test
description: Use of the commandline to shutdown or reboot windows
references:
- https://github.com/redcanaryco/atomic-red-team/blob/f339e7da7d05f6057fdfcdd3742bfcf365fee2a9/atomics/T1529/T1529.md
- https://learn.microsoft.com/en-us/windows-server/administration/windows-commands/shutdown
author: frack113
date: 2022-01-01
tags:
- attack.impact
- attack.t1529
logsource:
category: process_creation
product: windows
detection:
selection:
Image|endswith: '\shutdown.exe'
CommandLine|contains:
- '/r '
- '/s '
condition: selection
falsepositives:
- Unknown
level: medium
medium
Suspicious Execution of Shutdown to Log Out
Detects the rare use of the command line tool shutdown to logoff a user
status testauthor frack113id ec290c06-9b6b-4338-8b6b-095c0f284f10
view Sigma YAML
title: Suspicious Execution of Shutdown to Log Out
id: ec290c06-9b6b-4338-8b6b-095c0f284f10
status: test
description: Detects the rare use of the command line tool shutdown to logoff a user
references:
- https://github.com/redcanaryco/atomic-red-team/blob/9e5b12c4912c07562aec7500447b11fa3e17e254/atomics/T1529/T1529.md
- https://learn.microsoft.com/en-us/windows-server/administration/windows-commands/shutdown
author: frack113
date: 2022-10-01
tags:
- attack.impact
- attack.t1529
logsource:
category: process_creation
product: windows
detection:
selection:
Image|endswith: '\shutdown.exe'
CommandLine|contains: '/l'
condition: selection
falsepositives:
- Unknown
level: medium
informational
System Shutdown/Reboot - Linux
Adversaries may shutdown/reboot systems to interrupt access to, or aid in the destruction of, those systems.
status testauthor Igor Fits, oscd.communityid 4cb57c2f-1f29-41f8-893d-8bed8e1c1d2f
view Sigma YAML
title: System Shutdown/Reboot - Linux
id: 4cb57c2f-1f29-41f8-893d-8bed8e1c1d2f
status: test
description: Adversaries may shutdown/reboot systems to interrupt access to, or aid in the destruction of, those systems.
references:
- https://github.com/redcanaryco/atomic-red-team/blob/f339e7da7d05f6057fdfcdd3742bfcf365fee2a9/atomics/T1529/T1529.md
author: 'Igor Fits, oscd.community'
date: 2020-10-15
modified: 2022-11-26
tags:
- attack.impact
- attack.t1529
logsource:
product: linux
service: auditd
detection:
execve:
type: 'EXECVE'
shutdowncmd:
- 'shutdown'
- 'reboot'
- 'halt'
- 'poweroff'
init:
- 'init'
- 'telinit'
initselection:
- 0
- 6
condition: execve and (shutdowncmd or (init and initselection))
falsepositives:
- Legitimate administrative activity
level: informational
informational
System Shutdown/Reboot - MacOs
Adversaries may shutdown/reboot systems to interrupt access to, or aid in the destruction of, those systems.
status testauthor Igor Fits, Mikhail Larin, oscd.communityid 40b1fbe2-18ea-4ee7-be47-0294285811de
view Sigma YAML
title: System Shutdown/Reboot - MacOs
id: 40b1fbe2-18ea-4ee7-be47-0294285811de
status: test
description: Adversaries may shutdown/reboot systems to interrupt access to, or aid in the destruction of, those systems.
references:
- https://github.com/redcanaryco/atomic-red-team/blob/f339e7da7d05f6057fdfcdd3742bfcf365fee2a9/atomics/T1529/T1529.md
author: 'Igor Fits, Mikhail Larin, oscd.community'
date: 2020-10-19
modified: 2022-11-26
tags:
- attack.impact
- attack.t1529
logsource:
product: macos
category: process_creation
detection:
selection:
Image|endswith:
- '/shutdown'
- '/reboot'
- '/halt'
condition: selection
falsepositives:
- Legitimate administrative activity
level: informational