Detections

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

210 detections

Detects successful VPN connections from various common security devices logging to CommonSecurityLog. Monitoring successful VPN logins is crucial for tracking remote access and identifying potential unauthorized access, especially when correlated with other events like logins from unusual locations or impossible travel scenarios.
avatar
Shreyansh P@Shrey
avatar
Detections.ai Community
9 months ago
120113
Detects network connections to known C2 servers and payload delivery URLs associated with a PureRAT campaign. This activity is linked to a Vietnamese threat actor using AI to generate their toolset.
avatar
Elgonad .@elgonad
avatar
Detections.ai Community
9 months ago
1046
Detects the unique User-Agent string "A WinHTTP Example Program/1.0" used by the MuddyViper backdoor for C2 communications, as reported in the MuddyWater campaign.
avatar
Tim Peck@timpeck
avatar
Detections.ai Community
11 months ago
30132
This rule detects the use of common file transfer and remote access protocols (SSH, FTP, SMB, TELNET, FTPS, SMB.v3) communicating over non-standard ports. Adversaries often use non-standard ports to bypass firewall rules, evade detection, or obscure their command and control (C2) traffic. The rule specifically excludes the standard ports for these protocols to focus on anomalous behavior.
avatar
Rajuaravind Sankar@rajuaravindx
avatar
Splunkthat
11 months ago
190294
This detection rule identifies hosts where data archiving using 7-Zip is closely followed by network traffic to the temp.sh file-sharing service. This correlation suggests a potential data staging and exfiltration sequence, a TTP observed in the Lynx Ransomware campaign.
avatar
Dasom Kim@none028
avatar
Detections.ai Community
11 months ago
40170
Detects HTTP/HTTPS POST requests to known Lumma Stealer C2 domain
avatar
Nermin Smajic@NeoXS
avatar
Detections.ai Community
11 months ago
41157
Detects communication to known Command and Control (C2) servers associated with the Equation Group, as identified in the operational notes from the ShadowBrokers leak. This rule specifically looks for network connections to or from the hardcoded IP addresses linked to Equation Group C2 infrastructure.
avatar
SigmaHQ Detections@sigmaHQ
avatar
SigmaHQ
1 year ago
0044
The following analytic detects the use of default or publicly known named pipes associated with Cobalt Strike. It leverages Sysmon EventID 17 and 18 to identify specific named pipes commonly used by Cobalt Strike's Artifact Kit and Malleable C2 Profiles. This activity is significant because Cobalt Strike is a popular tool for adversaries to conduct post-exploitation tasks, and identifying its named pipes can reveal potential malicious activity. If confirmed malicious, this could indicate an active Cobalt Strike beacon, leading to unauthorized access, data exfiltration, or further lateral movement within the network.
Splunk Security@SplunkSecurity
avatar
Splunk Security Content
1 year ago
100247
This analytic detects suspicious data transfer activities involving the use of the `split` syscall with the `-b` option, which specifies the size of each output file. This technique can be used by attackers to evade detection by breaking large files into smaller parts, bypassing size-based security controls, and facilitating covert exfiltration of sensitive data. By monitoring for unusual or unauthorized use of the `split` syscall with a specified block size, this analytic helps identify potential data exfiltration attempts.
Splunk Security@SplunkSecurity
avatar
Splunk Security Content
1 year ago
0087
The following analytic detects the usage of `rclone.exe` with specific command-line arguments indicative of file transfer activities. It leverages data from Endpoint Detection and Response (EDR) agents, focusing on command-line executions and process details. This activity is significant as `rclone.exe` is often used by adversaries for data exfiltration, especially during ransomware attacks. If confirmed malicious, this behavior could lead to unauthorized data transfer, resulting in data breaches and potential loss of sensitive information. Immediate isolation of the affected endpoint and further investigation are recommended.
Splunk Security@SplunkSecurity
avatar
Splunk Security Content
1 year ago
1067
This analytic identifies the bulk creation of ransomware notes (e.g., .txt, .html, .hta files) on an infected machine. It leverages Sysmon EventCode 11 to detect multiple instances of these file types being created within a short time frame (10 seconds). A detection is triggered if 15 or more unique readme paths are observed. This activity is a strong indicator of an active ransomware attack, where the attacker is notifying the victim of the encryption. If confirmed malicious, this behavior could lead to widespread data encryption, rendering critical files inaccessible and potentially causing significant operational disruption.
Splunk Security@SplunkSecurity
avatar
Splunk Security Content
1 year ago
1160
The following analytic detects suspicious attempts to find credentials stored in password stores, indicating a potential attacker's effort to access sensitive login information. Password stores are critical repositories that contain valuable credentials, and unauthorized access to them can lead to significant security breaches. By monitoring for unusual or unauthorized activities related to password store access, this analytic helps identify potential credential theft attempts, allowing security teams to respond promptly and prevent unauthorized access to critical systems and data.
Splunk Security@SplunkSecurity
avatar
Splunk Security Content
1 year ago
0056
This analytic detects suspicious downloads from common file sharing and content delivery platforms using known living-off-the-land binaries (LOLBins) such as 'curl.exe', 'certutil.exe', 'msiexec.exe', 'powershell.exe', 'wmic.exe', and others. It leverages Cisco Network Visibility Module logs to correlate network flow activity with process context, including command-line arguments, process path, and parent process information. These tools are often abused by adversaries and malware to retrieve payloads from public hosting platforms such as GitHub, Discord CDN, Transfer.sh, or Pastebin. This detection helps identify potential initial access, payload staging, or command and control activity using legitimate services.
Splunk Security@SplunkSecurity
avatar
Splunk Security Content
1 year ago
1068
The following analytic detects MSIExec making network connections over ports 443 or 80. This behavior is identified by correlating process creation events from Endpoint Detection and Response (EDR) agents with network traffic logs. Typically, MSIExec does not perform network communication to the internet, making this activity unusual and potentially indicative of malicious behavior. If confirmed malicious, an attacker could be using MSIExec to download or communicate with external servers, potentially leading to data exfiltration, command and control (C2) communication, or further malware deployment.
Splunk Security@SplunkSecurity
avatar
Splunk Security Content
1 year ago
0051
The following analytic detects the use of PowerShell's download methods such as "DownloadString" and "DownloadData" from the WebClient class or Invoke-WebRequest and its aliases "IWR" or "Curl". It leverages data from Endpoint Detection and Response (EDR) agents, focusing on process execution logs that include command-line details. This activity can be significant as such methods and functions are commonly used in malicious PowerShell scripts to fetch and execute remote code. If confirmed malicious, this behavior could allow an attacker to download and run arbitrary code, potentially leading to unauthorized access, data exfiltration, or further compromise of the affected system.
Splunk Security@SplunkSecurity
avatar
Splunk Security Content
1 year ago
1047
The following analytic identifies the execution of RAR utilities to archive files on a system. It leverages data from Endpoint Detection and Response (EDR) agents, focusing on process names, GUIDs, and command-line arguments. This activity is significant as threat actors, including red-teamers and malware like DarkGate, use RAR archiving to compress and exfiltrate collected data from compromised hosts. If confirmed malicious, this behavior could lead to the unauthorized transfer of sensitive information to command and control servers, posing a severe risk to data confidentiality and integrity.
Splunk Security@SplunkSecurity
avatar
Splunk Security Content
1 year ago
1042
The analytic detects the use of Windows Curl.exe to download a file to a suspicious location, such as AppData, ProgramData, or Public directories. It leverages data from Endpoint Detection and Response (EDR) agents, focusing on command-line executions that include the -O or --output options. This activity is significant because downloading files to these locations can indicate an attempt to bypass security controls or establish persistence. If confirmed malicious, this behavior could lead to unauthorized code execution, data exfiltration, or further compromise of the system.
Splunk Security@SplunkSecurity
avatar
Splunk Security Content
1 year ago
0041
Detects HTTP responses containing JavaScript associated with ClickFix phishing kits. These kits manipulate the DOM to mimic browser verification pages and trick users into copying and executing malicious commands.
avatar
Tim Peck@timpeck
avatar
Detections.ai Community
1 year ago
21177
Adversaries may intentionally suppress or reduce the volume of core Cisco ASA syslog messages to evade detection or cover their tracks. This hunting search is recommended to proactively identify suspicious downward shifts or absences in key syslog message IDs, which may indicate tampering or malicious activity. Visualizing this data in Splunk dashboards enables security teams to quickly spot anomalies and investigate potential compromise. The rule specifically looks for drops in message IDs 302013 (Built inbound TCP connection), 302014 (Teardown TCP connection), 609002 (Teardown local-host management), and 710005 (TCP request discarded).
Splunk Security@SplunkSecurity
avatar
Splunk Security Content
1 year ago
1303,575
Detects Acreed infostealer's cryptocurrency clipper activity. This rule identifies when a host first communicates with a known Acreed C2 domain (`trustdomainnet.live`) to fetch malicious wallet addresses, and then communicates with a QR code generation API (`api.zile42o.dev`) used to replace legitimate QR codes with malicious ones.
avatar
Tim Peck@timpeck
avatar
Detections.ai Community
1 year ago
1094
This analytic detects the use of `curl.exe` with insecure flags such as `-k`, `--insecure`, `--proxy-insecure`, or `--doh-insecure` which disable TLS certificate validation. It leverages Cisco Network Visibility Module (NVM) flow data and process arguments to identify outbound connections initiated by curl where TLS checks were explicitly disabled. This behavior may indicate an attempt to bypass certificate validation to connect to potentially untrusted or malicious endpoints, a common tactic in red team operations, malware staging, or data exfiltration over HTTPS.
Splunk Security@SplunkSecurity
avatar
Splunk Security Content
1 year ago
4055
Page 4 of 10