Detections

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

6,208 detections

Detects the execution of 'curl.exe' on Windows systems. This activity can indicate an attempt to download files from a remote location, make web requests to external servers, or potentially be used for command and control communication. Adversaries often use tools like curl for ingress tool transfer or to retrieve additional malicious payloads.
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SigmaHQ Detections@sigmaHQ
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SigmaHQ
2 years ago
0020
Detects the execution of 'curl.exe' when a custom User-Agent string is specified using either the '-A' or '--user-agent' command-line options. This behavior can be indicative of an adversary attempting to mimic legitimate web traffic while using a non-standard User-Agent to evade detection or to identify themselves to a C2 server.
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SigmaHQ Detections@sigmaHQ
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SigmaHQ
2 years ago
0020
NKN is a networking service using blockchain technology to support a decentralized network of peers. While there are legitimate uses for it, it can also be used as a C2 channel. This rule looks for a DNS request to the ma>
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SigmaHQ Detections@sigmaHQ
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SigmaHQ
2 years ago
0020
Detects when a password-protected ZIP archive is opened on a Windows system, specifically looking for archives with suspicious filenames commonly used in phishing or social engineering attacks (e.g., 'invoice', 'order', 'payment'). This rule leverages Windows Security Event ID 5379, which indicates a sensitive privilege use, and filters for events related to the Microsoft_Windows_Shell_ZipFolder:filename provider, combined with a list of suspicious keywords in the TargetName field.
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SigmaHQ Detections@sigmaHQ
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SigmaHQ
2 years ago
1020
This rule detects the installation of a TAP (Tunnel Adapter) driver, specifically looking for 'tap0901' in the service's ImagePath. TAP drivers are commonly used by VPN software like OpenVPN to create virtual network interfaces, which can be leveraged for tunneling and data exfiltration. The detection aims to identify potential preparation for data exfiltration using tunneling techniques.
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SigmaHQ Detections@sigmaHQ
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SigmaHQ
2 years ago
0020
Detects DNS queries made by "AppInstaller.EXE" when attempting to load or install an AppX package from a referenced URL. This activity is indicative of the AppInstaller being used, which is the default handler for the "ms-appinstaller" URI scheme. This can be abused by adversaries for ingress tool transfer.
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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
Detects suspicious usage of curl.exe to download files to sensitive or temporary locations on Windows systems. This rule specifically looks for curl.exe processes that output downloaded content to common temporary directories, user-specific application data folders, public user folders, or the desktop, often with suspicious file extensions. This behavior is frequently associated with malware staging or initial access techniques.
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SigmaHQ Detections@sigmaHQ
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SigmaHQ
2 years ago
0020
Detects the execution of 'IEExec.exe' with command-line arguments containing 'http://' or 'https://', indicating an attempt to download and execute files from a remote web server. This utility is part of the .NET Framework and can be abused by adversaries for ingress tool transfer.
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SigmaHQ Detections@sigmaHQ
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SigmaHQ
2 years ago
0020
Detects the execution of "Ldifde.exe" with the import flag "-i" and a file specified by "-f". This can be abused to import data, potentially from remote HTTP sources, leading to arbitrary file downloads or data injection.
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SigmaHQ Detections@sigmaHQ
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SigmaHQ
2 years ago
0020
Detects the use of 'curl.exe' to download files by looking for specific command-line arguments such as '-O', '--remote-name', or '--output'. This activity can indicate an adversary transferring tools or other files into a compromised environment.
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SigmaHQ Detections@sigmaHQ
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SigmaHQ
2 years ago
0019
This rule detects sign-in attempts originating from IP addresses identified as malicious by Azure AD Identity Protection, specifically when these attempts are characterized by a high failure rate. This indicates potential brute-force attacks, credential stuffing, or other unauthorized access attempts from known bad IP addresses.
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SigmaHQ Detections@sigmaHQ
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SigmaHQ
2 years ago
0019
Detects the use of the 'wget' utility to download and create files within common temporary directories like '/tmp' or '/var/tmp' on Linux systems. This activity can be indicative of an adversary performing ingress tool transfer or staging malicious files.
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SigmaHQ Detections@sigmaHQ
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SigmaHQ
2 years ago
2019
Detects when legitimate Windows applications, including Microsoft Office programs and various Living Off The Land Binaries (LOLBINs), create archive files (ZIP, RAR, 7Z, diagcab, appx). This behavior is often indicative of malicious activity, such as staging data for exfiltration or dropping malicious payloads, as these applications typically should not be creating archives.
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SigmaHQ Detections@sigmaHQ
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SigmaHQ
2 years ago
0019
This rule detects the use of 'powercat' or 'powercat.ps1' within PowerShell classic logs. Powercat is a PowerShell-based network utility similar to Netcat, often used by adversaries for network communication, including reverse shells, bind shells, and file transfers, potentially bypassing traditional network controls. This activity is indicative of command and control communication or lateral movement using non-application layer protocols.
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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
Detects the use of Plink (PuTTY Link) for suspicious remote port forwarding to a local port. This technique can be used by adversaries to bypass network restrictions and establish tunnels for command and control or data exfiltration.
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SigmaHQ Detections@sigmaHQ
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SigmaHQ
2 years ago
0019
Detects attempts to decompress Gzip archives using PowerShell's GZipStream::Decompress method. This technique can be used by adversaries to unpack malicious payloads that have been compressed to evade detection.
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SigmaHQ Detections@sigmaHQ
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SigmaHQ
2 years ago
0019
Detects the creation of a suspicious file by 'svchost.exe' in the 'Personalization\LockScreenImage' directory, specifically looking for files that are not in the 'C:\Windows\' directory and do not have common image extensions like '.jpg', '.jpeg', or '.png'. This behavior can indicate an adversary attempting to download or stage malicious files using the 'desktopimgdownldr' functionality, which is often associated with T1105 (Ingress Tool Transfer).
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SigmaHQ Detections@sigmaHQ
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SigmaHQ
2 years ago
0018
Detects the execution of Ngrok, a legitimate utility often abused by threat actors for port forwarding and tunneling. This allows them to expose local services to the internet, bypassing firewalls and network restrictions. The rule specifically looks for common command-line arguments used with Ngrok, such as those for tunneling specific TCP ports (e.g., 139, 445, 3389, 5985, 5986), HTTP services, or configuration file usage.
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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
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