Detections

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

5,151 detections

This YARA rule detects the OrcusRAT backdoor by identifying specific bytecode patterns associated with its functionalities. These functionalities include retrieving TCP connections, gathering operating system information, taking screenshots, extracting passwords, and processing keylogger actions. The rule looks for a combination of these patterns within a file that also has a valid DOS header (MZ signature).
ReversingLabs Yara@ReversingLabsYara
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ReversingLabs Yara
2 years ago
0032
This YARA rule detects the NoodRAT backdoor by identifying specific byte sequences (patterns) associated with its core functionalities. These functionalities include changing the system name, decrypting configuration data, encrypting and sending data, and receiving and decrypting data. The rule specifically targets Linux ELF executables, indicated by the magic byte `0x464C457F` at offset 0.
ReversingLabs Yara@ReversingLabsYara
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ReversingLabs Yara
2 years ago
0035
Detects a network connection initiated by programs or processes running from suspicious or uncommon file system locations. This often indicates malware execution or persistence from areas not typically used by legitimate applications for network communication.
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SigmaHQ Detections@sigmaHQ
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SigmaHQ
2 years ago
2020
Detects the execution of Impacket's psexec.py by monitoring for specific file share access patterns on the IPC$ share. The rule looks for EventID 5145 (a detailed file share access event) where the ShareName is '\\*\IPC$' and the RelativeTargetName contains 'RemCom_stdin', 'RemCom_stdout', or 'RemCom_stderr'. These file names are characteristic of how Impacket's psexec.py communicates with the remote service.
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SigmaHQ Detections@sigmaHQ
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SigmaHQ
2 years ago
3088
Detects Kerberos Ticket-Granting Service (TGS) requests that utilize RC4 encryption. This is often indicative of Kerberoasting attacks, where adversaries request service tickets for Service Principal Names (SPNs) and then attempt to crack the RC4-encrypted hash offline to obtain plaintext credentials. The rule specifically excludes requests from computer accounts (service accounts ending with '$') to reduce false positives.
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SigmaHQ Detections@sigmaHQ
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SigmaHQ
2 years ago
0063
This rule detects suspicious command-line patterns indicative of reverse shell attempts. It looks for various common techniques used to establish a reverse shell, including bash, sh, netcat, socat, Perl, Python, Ruby, and PHP one-liners that connect back to an attacker-controlled host. The rule also includes patterns for xterm reverse shells and specific shell commands often used in conjunction with reverse shells.
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SigmaHQ Detections@sigmaHQ
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SigmaHQ
2 years ago
1046
This rule detects the usage of cleartext protocols over a network by monitoring firewall logs for allowed connections to specific destination ports commonly associated with unencrypted services. These ports include HTTP (80, 8080), FTP (21), Telnet (23), and various database or application-specific ports (e.g., 1433, 3306, 1521, 27017, 50000, 11211, 15672, 5900-5904). The rule specifically looks for 'forward' or 'accept' actions, or connections not marked as 'blocked', indicating active cleartext communication. The primary goal is to identify potential credential exposure or sensitive data transmission over insecure channels.
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SigmaHQ Detections@sigmaHQ
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SigmaHQ
2 years ago
0044
This rule detects PowerShell script blocks that utilize .NET's SslStream for establishing encrypted network connections. Specifically, it looks for the use of 'System.Net.Security.SslStream', 'Net.Security.RemoteCertificateValidationCallback', and '.AuthenticateAsClient' which are indicative of a client-side SSL/TLS connection being programmatically established, potentially for command and control (C2) purposes to evade detection.
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SigmaHQ Detections@sigmaHQ
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SigmaHQ
2 years ago
1042
This rule detects RDP traffic communicating with the loopback address (127.0.0.1 or ::1) on either the source or destination port 3389, specifically looking for Windows Filtering Platform (WFP) events (EventID 5156). This behavior is indicative of RDP over a reverse SSH tunnel, where RDP traffic is redirected locally to bypass network restrictions or for covert communication. The rule explicitly filters out events originating from 'AppContainer Loopback' and known Thor processes to reduce false positives.
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SigmaHQ Detections@sigmaHQ
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SigmaHQ
2 years ago
0041
Detects the execution of Netcat (nc.exe, ncat.exe, netcat.exe) with suspicious command-line arguments often associated with establishing listener modes, reverse shells, or proxy connections. Netcat is a versatile networking utility that can be used by adversaries for command and control (C2) communication, data exfiltration, or creating backdoors, often leveraging non-application layer protocols.
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SigmaHQ Detections@sigmaHQ
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SigmaHQ
2 years ago
1038
Detects a network connection initiated from a process located in the "C:\Users\Public" folder. Attackers are known to drop their malicious payloads and malware in this directory as it's writable by everyone. This rule helps hunt for potential suspicious or uncommon activity in the environment.
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SigmaHQ Detections@sigmaHQ
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SigmaHQ
2 years ago
0037
Detects the use of the 'spoolss' named pipe over SMB, which can be leveraged to trigger NTLM authentication from a target machine with the print spooler service enabled. This technique is often used in NTLM relay attacks or other forms of printer spooler abuse to gain unauthorized access or escalate privileges.
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SigmaHQ Detections@sigmaHQ
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SigmaHQ
2 years ago
0037
This rule detects suspicious DNS queries specifically targeting 'api.telegram.org'. This domain is used by Telegram Bot API, which can be leveraged by various types of malware (e.g., RATs, ransomware) for command and control (C2) or data exfiltration. Monitoring these queries helps identify systems potentially communicating with malicious Telegram bots.
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SigmaHQ Detections@sigmaHQ
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SigmaHQ
2 years ago
3036
Detects potential Command and Control (C2) communication associated with the Small Sieve malware. This rule specifically looks for HTTP GET requests to 'api.telegram.org' with a specific chat_id and 'text=com/' in the URI, which are indicators of Small Sieve's use of the Telegram Bot API for C2.
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SigmaHQ Detections@sigmaHQ
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SigmaHQ
2 years ago
0034
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. This rule helps hunt for potentially anomalous or suspicious communications.
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SigmaHQ Detections@sigmaHQ
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SigmaHQ
2 years ago
2033
Detects svchost.exe initiating an outbound network connection on TCP port 3389 (RDP) to a loopback address (127.0.0.0/8 or ::1/128). This behavior is indicative of RDP traffic being tunneled, potentially via a reverse SSH tunnel, to bypass network restrictions or for covert remote access.
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SigmaHQ Detections@sigmaHQ
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SigmaHQ
2 years ago
0033
Detects potential command and control (C2) beaconing activity to domains identified as being used in the 'Operation Triangulation' campaign, which targeted iOS devices with 0-day exploits. This rule specifically looks for connections to a list of known malicious domains via proxy logs.
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SigmaHQ Detections@sigmaHQ
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SigmaHQ
2 years ago
0032
Detects Border Gateway Protocol (BGP) authentication failures, which can indicate attempts to brute force BGP peer authentication. Such attacks aim to manipulate routing information, potentially leading to traffic redirection or denial of service.
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SigmaHQ Detections@sigmaHQ
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SigmaHQ
2 years ago
0032
Detects the remote installation of a print driver, which is a possible indication of the exploitation of PrintNightmare (CVE-2021-1675, CVE-2021-34527). The occurrence of print drivers being installed remotely via RPC functions should be rare, as print drivers are normally installed locally or through group policy.
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SigmaHQ Detections@sigmaHQ
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SigmaHQ
2 years ago
0031
This rule detects outbound network connections to ngrok tunneling service endpoints. Ngrok is a legitimate tool that can be used to expose local servers to the internet, but it is also frequently leveraged by malicious actors for data exfiltration, command and control, and bypassing network restrictions. Detection of communication to these specific ngrok domains could indicate unauthorized use of the service for malicious purposes.
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SigmaHQ Detections@sigmaHQ
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SigmaHQ
2 years ago
1030
Detects the download of potentially malicious file types (executables, scripts, documents, archives, etc.) from domains using suspicious or commonly abused Top-Level Domains (TLDs). This rule aims to identify initial access attempts often associated with phishing or drive-by download campaigns.
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SigmaHQ Detections@sigmaHQ
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SigmaHQ
2 years ago
1030
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