Rule Library

Sigma Rules

61 rules found

3,707Total
3,116Detection
451Emerging
137Hunting
Detectionmediumtest

Local Network Connection Initiated By Script Interpreter

Detects a script interpreter (Wscript/Cscript) initiating a local network connection to download or execute a script hosted on a shared folder.

WindowsNetwork Connection
TA0011 · Command and ControlT1105 · Ingress Tool Transfer
François HubautSun Aug 28windows
Detectionhightest

Outbound Network Connection Initiated By Script Interpreter

Detects a script interpreter wscript/cscript opening a network connection to a non-local network. Adversaries may use script to download malicious payloads.

WindowsNetwork Connection
TA0011 · Command and ControlT1105 · Ingress Tool Transfer
François Hubaut+1Sun Aug 28windows
Detectionmediumtest

Potentially Suspicious Wuauclt Network Connection

Detects the use of the Windows Update Client binary (wuauclt.exe) to proxy execute code and making network connections. One could easily make the DLL spawn a new process and inject to it to proxy the network connection and bypass this rule.

WindowsNetwork Connection
TA0005 · Defense EvasionT1218 · System Binary Proxy Execution
Roberto Rodriguez (Cyb3rWard0g)+1Mon Oct 12windows
Emerging Threathightest

Potential Pikabot C2 Activity

Detects the execution of rundll32 that leads to an external network connection. The malware Pikabot has been seen to use this technique to initiate C2-communication through hard-coded Windows binaries.

WindowsNetwork Connection
TA0011 · Command and ControlT1573 · Encrypted Channeldetection.emerging-threats
Andreas Braathen (mnemonic.io)Fri Oct 272023
Emerging Threathightest

Potential Compromised 3CXDesktopApp Beaconing Activity - Netcon

Detects potential beaconing activity to domains related to 3CX 3CXDesktopApp compromise

WindowsNetwork Connection
TA0011 · Command and Controldetection.emerging-threats
Nasreddine Bencherchali (Nextron Systems)Wed Mar 292023
Threat Huntmediumtest

Dfsvc.EXE Network Connection To Non-Local IPs

Detects network connections from "dfsvc.exe" used to handled ClickOnce applications to non-local IPs

WindowsNetwork Connection
TA0002 · ExecutionT1203 · Exploitation for Client Executiondetection.threat-hunting
Nasreddine Bencherchali (Nextron Systems)Mon Jun 12windows
Threat Hunthightest

Dfsvc.EXE Initiated Network Connection Over Uncommon Port

Detects an initiated network connection over uncommon ports from "dfsvc.exe". A utility used to handled ClickOnce applications.

WindowsNetwork Connection
TA0002 · ExecutionT1203 · Exploitation for Client Executiondetection.threat-hunting
Nasreddine Bencherchali (Nextron Systems)Mon Jun 12windows
Threat Huntmediumtest

Dllhost.EXE Initiated Network Connection To Non-Local IP Address

Detects Dllhost.EXE initiating a network connection to a non-local IP address. Aside from Microsoft own IP range that needs to be excluded. Network communication from Dllhost will depend entirely on the hosted DLL. An initial baseline is recommended before deployment.

WindowsNetwork Connection
TA0005 · Defense EvasionT1218 · System Binary Proxy ExecutionTA0002 · ExecutionT1559.001 · Component Object Model+1
bartblazeMon Jul 13windows
Threat Huntmediumtest

HH.EXE Initiated HTTP Network Connection

Detects a network connection initiated by the "hh.exe" process to HTTP destination ports, which could indicate the execution/download of remotely hosted .chm files.

WindowsNetwork Connection
TA0005 · Defense EvasionT1218.001 · Compiled HTML Filedetection.threat-hunting
Nasreddine Bencherchali (Nextron Systems)Wed Oct 05windows
Threat Huntlowtest

Msiexec.EXE Initiated Network Connection Over HTTP

Detects a network connection initiated by an "Msiexec.exe" process over port 80 or 443. Adversaries might abuse "msiexec.exe" to install and execute remotely hosted packages. Use this rule to hunt for potentially anomalous or suspicious communications.

WindowsNetwork Connection
TA0005 · Defense EvasionT1218.007 · Msiexecdetection.threat-hunting
François HubautSun Jan 16windows
Threat Huntlowtest

Network Connection Initiated By PowerShell Process

Detects a network connection that was initiated from a PowerShell process. Often times malicious powershell scripts download additional payloads or communicate back to command and control channels via uncommon ports or IPs. Use this rule as a basis for hunting for anomalies.

WindowsNetwork Connection
TA0002 · ExecutionT1059.001 · PowerShelldetection.threat-hunting
Florian Roth (Nextron Systems)Mon Mar 13windows
Threat Huntmediumtest

Potentially Suspicious Azure Front Door Connection

Detects connections with Azure Front Door (known legitimate service that can be leveraged for C2) that fall outside of known benign behavioral baseline (not using common apps or common azurefd.net endpoints)

WindowsNetwork Connection
TA0011 · Command and ControlT1102.002 · Bidirectional CommunicationT1090.004 · Domain Frontingdetection.threat-hunting
Isaac DunhamThu Nov 07windows
Threat Huntmediumtest

Network Connection Initiated From Users\Public Folder

Detects a network connection initiated from a process located in the "C:\Users\Public" folder. Attacker are known to drop their malicious payloads and malware in this directory as its writable by everyone. Use this rule to hunt for potential suspicious or uncommon activity in your environement.

WindowsNetwork Connection
TA0011 · Command and ControlT1105 · Ingress Tool Transferdetection.threat-hunting
Florian Roth (Nextron Systems)Fri May 31windows