Detections

Explore public detection logic contributed by the community across SIEM and rule languages.

5,151 detections

This rule detects the use of Background Intelligent Transfer Service (BITS) to connect to IP addresses directly, rather than fully qualified domain names (FQDNs). This behavior can be indicative of malicious activity, as adversaries often use BITS for command and control or data transfer, and connecting to IP addresses can be a way to bypass DNS-based security controls or to obscure the true destination.
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SigmaHQ Detections@sigmaHQ
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SigmaHQ
2 years ago
1030
Detects a threat actor creating a file named `iertutil.dll` in the `C:\Program Files\Internet Explorer\` directory over the network for a DCOM InternetExplorer DLL Hijack scenario. This rule specifically looks for EventID 5145 (a network share access event) where the target file path ends with `\Internet Explorer\iertutil.dll` and the `SubjectUserName` does not end with a `$` (indicating a machine account, which is filtered out to reduce false positives).
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SigmaHQ Detections@sigmaHQ
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SigmaHQ
2 years ago
1030
Detects network access to the 'protected_storage' service, specifically targeting the IPC$ share. This activity is often associated with attempts to extract DPAPI domain backup keys from Domain Controllers, a technique used for credential access and lateral movement.
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SigmaHQ Detections@sigmaHQ
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SigmaHQ
2 years ago
1030
Detects potential beaconing activity from the 3CXDesktopApp to known malicious domains associated with the 3CX supply chain compromise. This rule identifies outbound network connections initiated by the 3CXDesktopApp.exe process to a specific list of suspicious hostnames, indicating potential command and control communication.
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SigmaHQ Detections@sigmaHQ
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SigmaHQ
2 years ago
0029
Detects the use of the spoolss named pipe over SMB. This can be used to trigger NTLM authentication from machines with the spooler service enabled, often as part of NTLM relay attacks or credential harvesting.
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SigmaHQ Detections@sigmaHQ
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SigmaHQ
2 years ago
1029
Detects instances where the svchost.exe process, specifically hosting the RDP terminal services, initiates outbound network connections to target systems on standard HTTP (TCP port 80) or HTTPS (TCP port 443) ports. This behavior is indicative of RDP tunneling, where RDP traffic is encapsulated within web protocols to bypass network restrictions or evade detection.
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SigmaHQ Detections@sigmaHQ
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SigmaHQ
2 years ago
0029
Detects various process execution behaviors associated with the Lazarus Group, including attempts to dump SAM registry hive, network connection enumeration using netstat, network share discovery patterns, persistence mechanisms involving common program data directories, and rundll32 execution with specific file extensions.
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SigmaHQ Detections@sigmaHQ
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SigmaHQ
2 years ago
0028
Detects a bash process initiating an outbound network connection to a remote IP address, which is a common indicator of a reverse shell. This rule specifically looks for '/bin/bash' processes making network connections, excluding connections to localhost or unspecified addresses.
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SigmaHQ Detections@sigmaHQ
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SigmaHQ
2 years ago
1028
Detects the execution of '3proxy.exe', a tiny free proxy server, based on its image name, description, or specific command-line parameters. This tool can be used by adversaries for command and control activities, specifically for proxying network traffic.
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SigmaHQ Detections@sigmaHQ
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SigmaHQ
2 years ago
1028
Detects outbound network connections to known cryptocurrency mining pool domains. This activity is often indicative of resource hijacking (cryptojacking) where an attacker uses a compromised system's resources to mine cryptocurrency without the owner's consent. The rule specifically targets a comprehensive list of domains associated with various mining pools, primarily for Monero (XMR) and other cryptocurrencies.
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SigmaHQ Detections@sigmaHQ
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SigmaHQ
2 years ago
0027
This rule detects the first-time observation of remote named pipe connections, excluding a predefined list of common and legitimate named pipes. This behavior is often indicative of lateral movement or remote execution using named pipes, which attackers commonly leverage to move within a network or execute code on remote systems. The rule specifically looks for connections to '\\*\IPC$', a common administrative share used for interprocess communication over a network. By filtering out known legitimate named pipes, the rule aims to reduce false positives and highlight potentially malicious activity.
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SigmaHQ Detections@sigmaHQ
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SigmaHQ
2 years ago
0026
This rule detects instances where the 'winlogon.exe' process initiates outbound network connections to public IP addresses. Winlogon.exe is a critical Windows component responsible for user logon/logoff and the secure attention sequence. Typically, winlogon.exe should not be making outbound network connections to public IPs. Such activity could indicate compromise, potentially by malware like BlackLotus, which has been observed to leverage winlogon.exe for malicious purposes, including command and control or data exfiltration.
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SigmaHQ Detections@sigmaHQ
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SigmaHQ
2 years ago
1026
Detects the execution of 'curl.exe' with command-line flags that disable security checks for proxy or DNS over HTTPS (DoH) connections. This behavior can indicate an attempt to bypass security controls or establish covert communication channels.
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SigmaHQ Detections@sigmaHQ
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SigmaHQ
2 years ago
1026
Detects a BITS transfer job downloading file(s) from a direct IP address. This technique is often used by adversaries for defense evasion and persistence, as BITS jobs can operate in the background, bypass some firewall rules, and persist across reboots.
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SigmaHQ Detections@sigmaHQ
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SigmaHQ
2 years ago
0025
Detects the usage of the ".Net.Sockets.TCPClient" class within PowerShell, which is commonly abused to establish remote connections and reverse shells. This technique is notably used by tools like Nishang's "Invoke-PowerShellTcpOneLine" and other malicious scripts to create outbound network connections for command and control or data exfiltration.
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SigmaHQ Detections@sigmaHQ
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SigmaHQ
2 years ago
0025
This rule detects the execution of PsExec or PAExec by monitoring network share access to the IPC$ share. Specifically, it looks for access to named pipes ending with '-stdin', '-stdout', or '-stderr', which are characteristic of PsExec/PAExec communication. The rule filters out instances where the service name starts with 'PSEXESVC', indicating the standard Sysinternals PsExec service, to reduce false positives for legitimate PsExec usage or when the attacker uses a different PsExec client.
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SigmaHQ Detections@sigmaHQ
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SigmaHQ
2 years ago
0024
Detects a threat actor creating a file named `wbemcomn.dll` in the `C:\Windows\System32\wbem\` directory over the network for a WMI DLL Hijack scenario. This is identified by monitoring Windows Security Event ID 5145 for file creations ending with `\wbem\wbemcomn.dll` and filtering out legitimate system accounts (those ending with '$').
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SigmaHQ Detections@sigmaHQ
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SigmaHQ
2 years ago
2024
Detects cases where ngrok, a legitimate reverse proxy tool, is used to forward traffic to the local Remote Desktop Protocol (RDP) port. This activity can indicate malicious behavior, as adversaries often use tools like ngrok for command and control, bypassing firewalls, or establishing persistent remote access to compromised systems.
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SigmaHQ Detections@sigmaHQ
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SigmaHQ
2 years ago
0024
Detects the presence of Silence EmpireDNSAgent by looking for specific PowerShell script block text patterns associated with both the Empire post-exploitation framework and Dnscat2 tunneling. The rule combines keywords related to system shutdown/reboot, process manipulation, and DNS tunneling techniques used by this malware.
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SigmaHQ Detections@sigmaHQ
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SigmaHQ
2 years ago
0024
This rule detects the execution of 'plink.exe' with command-line arguments indicative of RDP tunneling. Specifically, it looks for 'plink.exe' combined with ':127.0.0.1:3389' or ':3389' along with '-P 443' or '-P 22'. This activity suggests an adversary is using Plink to establish a tunnel, potentially to exfiltrate data or maintain covert access to a remote desktop session.
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SigmaHQ Detections@sigmaHQ
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SigmaHQ
2 years ago
1024
Detects connections made by Microsoft BITSAdmin to domains using uncommon Top-Level Domains (TLDs). This can indicate command and control activity or data exfiltration where an adversary is attempting to blend in with legitimate traffic but using less common TLDs to avoid common filtering.
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SigmaHQ Detections@sigmaHQ
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SigmaHQ
2 years ago
1023
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