Detections

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

5,155 detections

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
Detects exploitation attempts using the JNDI-Exploit-Kit by looking for specific URI patterns in web server logs. These patterns are indicative of various JNDI injection payloads designed to achieve remote code execution, reverse shells, or memory shell deployments on vulnerable applications like Tomcat, Jetty, Weblogic, JBoss, Websphere, and Spring.
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SigmaHQ Detections@sigmaHQ
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SigmaHQ
2 years ago
1023
This rule detects a suspicious command sequence often associated with the JexBoss exploitation tool. Specifically, it looks for the execution of 'bash -c /bin/bash' followed by a network connection attempt using '&/dev/tcp/'. This combination indicates an attempt to establish a reverse shell or exfiltrate data over TCP.
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SigmaHQ Detections@sigmaHQ
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SigmaHQ
2 years ago
0022
Detects reconnaissance activities targeting privileged Active Directory users or groups by monitoring Windows Security Event ID 4661. The rule specifically looks for access attempts to objects identified as privileged users or groups based on their Security Identifier (SID) suffixes or names containing 'admin'. It filters out activity from machine accounts to reduce false positives.
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SigmaHQ Detections@sigmaHQ
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SigmaHQ
2 years ago
1022
Detects remote service activity by monitoring access to the 'svcctl' named pipe via the IPC$ share. This activity is indicative of an attacker attempting to interact with services on a remote system, often as part of lateral movement or persistence efforts.
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SigmaHQ Detections@sigmaHQ
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SigmaHQ
2 years ago
0021
This rule detects potential Command and Control (C2) communication associated with the Goofy Guineapig backdoor. It specifically looks for HTTP/S requests originating from a user agent string characteristic of the malware ('Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/54.0.2840.71 Safari/537.36') communicating with the domain 'static.tcplog.com'. This combination of user agent and destination domain is indicative of Goofy Guineapig C2 activity.
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SigmaHQ Detections@sigmaHQ
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SigmaHQ
2 years ago
0020
Detects a network connection initiated by the "hh.exe" process to HTTP destination ports (80 or 443). This activity could indicate the execution or download of remotely hosted Compiled HTML (.chm) files, which can be abused by adversaries to conceal and execute malicious code. This technique is often used for defense evasion and can bypass application controls.
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SigmaHQ Detections@sigmaHQ
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SigmaHQ
2 years ago
0020
Adversaries may steal data by exfiltrating it over an un-encrypted network protocol other than that of the existing command and control channel. The data may also be sent to an alternate network location from the main command and control server. This rule detects suspicious outbound SMTP connections by looking for connections to common SMTP ports (25, 587, 465, 2525) from processes that are not common mail client applications like Thunderbird or Outlook, or Microsoft Exchange Server processes.
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SigmaHQ Detections@sigmaHQ
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SigmaHQ
2 years ago
0020
This rule detects the execution of the `nslookup` command specifically querying for LDAP service records (`_ldap._tcp.dc._msdcs.`). This type of query is often used during the reconnaissance phase by attackers to discover Active Directory domain controllers and their associated services within a network. This activity can indicate an adversary attempting to map out the network infrastructure.
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SigmaHQ Detections@sigmaHQ
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SigmaHQ
2 years ago
0020
Detects the use of 'nltest.exe' with command-line arguments indicative of reconnaissance activity, specifically targeting domain trust discovery and domain controller enumeration. Adversaries often use 'nltest.exe' to gather information about the network environment, which can aid in lateral movement and privilege escalation within Windows domains.
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SigmaHQ Detections@sigmaHQ
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SigmaHQ
2 years ago
5020
Detects a process that initiated a network connection over ports 5985 or 5986 from a non-network service account. This could potentially indicate a remote PowerShell connection, often associated with Windows Remote Management (WinRM). The rule filters out connections from common network service accounts and localhost to reduce false positives.
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SigmaHQ Detections@sigmaHQ
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SigmaHQ
2 years ago
0019
This rule detects the usage of the PowerShell cmdlet `Test-NetConnection` to probe network connectivity to a specified computer name and port, specifically looking for connections to ports other than the commonly used 80 or 443. This behavior can indicate an adversary attempting to establish or test communication channels over non-standard ports, potentially to bypass network defenses or obscure command and control activities.
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SigmaHQ Detections@sigmaHQ
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SigmaHQ
2 years ago
0019
This rule detects outbound network connections initiated by the `cmstp.exe` process. `cmstp.exe` is the Microsoft Connection Manager Profile Installer, and it is uncommon for this legitimate binary to initiate outbound network connections. Such activity could indicate an adversary is abusing `cmstp.exe` to proxy execution of malicious code, potentially for defense evasion or UAC bypass, by loading malicious INF files or scriptlets from remote servers.
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SigmaHQ Detections@sigmaHQ
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SigmaHQ
2 years ago
0018
Detects network connections to the Notion API (api.notion.com) from processes that are not recognized legitimate Notion applications or common web browsers. This rule aims to identify potential covert command and control (C2) channels, specifically referencing tools like "OffensiveNotion C2" which leverage Notion's infrastructure for malicious communication.
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SigmaHQ Detections@sigmaHQ
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SigmaHQ
2 years ago
0017
Detects an executable initiating a network connection to "ngrok" tunneling domains. Attackers were seen using this "ngrok" in order to store their second stage payloads and malware. While communication with such domains can be legitimate, often times is a sign of either data exfiltration by malicious actors or additional download.
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SigmaHQ Detections@sigmaHQ
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SigmaHQ
2 years ago
0017
Detects suspicious network connections initiated by specific Windows binaries (regsvr32.exe, rundll32.exe, dllhost.exe) when they are executed without any command-line parameters. This behavior can indicate an attempt to evade detection by leveraging legitimate system binaries for malicious network communication, potentially associated with malware like Raspberry Robin.
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SigmaHQ Detections@sigmaHQ
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SigmaHQ
2 years ago
0017
This rule detects PowerShell scripts that add a Name Resolution Policy Table (NRPT) rule. An NRPT rule can be used to bypass the default DNS server and force DNS queries for specific namespaces to a different, specified DNS server. This technique can be used by adversaries to redirect traffic, potentially for command and control, data exfiltration, or to evade network filtering.
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SigmaHQ Detections@sigmaHQ
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SigmaHQ
2 years ago
0017
Detects programs that connect to known malware callback ports based on statistical analysis from two different sandbox system databases. This rule identifies outbound network connections to a specific list of destination ports that have been historically associated with malware command and control (C2) communications. It filters out connections to local IP ranges and common system directories to reduce false positives.
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SigmaHQ Detections@sigmaHQ
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SigmaHQ
2 years ago
0016
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