Detections

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

6,208 detections

This rule identifies when the HTTP DELETE method is used within the Microsoft Graph API. This can indicate administrative activities such as deleting users, groups, or other resources. The rule specifically looks for network HTTP events where the product event type is 'Microsoft Graph Activity' and the HTTP method is 'DELETE'. It excludes IP addresses within a specific Azure CIDR range (20.151.0.0/16) to reduce noise from internal Azure operations. Further tuning can be applied to target specific API endpoints or user agents.
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Google SecOps@GoogleSecOps
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Google SecOps Detection Rules
2 years ago
1040
Detects a non-browser process interacting with the Google API which could indicate the use of a covert C2 such as Google Sheet C2 (GC2-sheet). The rule specifically looks for connections to Google API domains from processes that are not common web browsers or Google-related applications, aiming to identify potentially malicious command and control activity.
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SigmaHQ Detections@sigmaHQ
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SigmaHQ
2 years ago
0013
Detects HTTP requests to low reputation TLDs (e.g. .xyz, .top, .ru) or ending in suspicious file extensions (.exe, .dll, .hta), which may indicate malicious activity.
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SigmaHQ Detections@sigmaHQ
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SigmaHQ
2 years ago
000
An adversary may use legitimate desktop support and remote access software, such as Team Viewer, Go2Assist, LogMein, AmmyyAdmin, etc, to establish an interactive command and control channel to target systems within networks.
These services are commonly used as legitimate technical support software, and may be allowed by application control within a target environment.
Remote access tools like VNC, Ammyy, and Teamviewer are used frequently when compared with other legitimate software commonly used by adversaries. (Citation: Symantec Living off the Land)
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SigmaHQ Detections@sigmaHQ
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SigmaHQ
2 years ago
001
Detects a non-browser process interacting with the Google API which could indicate the use of a covert C2 such as Google Sheet C2 (GC2-sheet)
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SigmaHQ Detections@sigmaHQ
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SigmaHQ
2 years ago
000
Detects potential exploitation of CVE-2024-1212, an unauthenticated command injection vulnerability in Progress Kemp LoadMaster. The rule specifically looks for GET requests to the '/access/set' API with the parameters 'param=enableapi' and 'value=1', combined with an "Authorization" header containing a base64 encoded value with uncommon characters, indicative of an attempted exploit.
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SigmaHQ Detections@sigmaHQ
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SigmaHQ
2 years ago
0026
This rule identifies outbound network connections to Autonomous System Numbers (ASNs) that are present in a predefined watchlist named 'suspicious_asn'. It leverages geo-IP enrichment to extract the ASN of the target IP address and compares it against the watchlist. The rule is designed to detect communication with potentially malicious or suspicious network infrastructure.
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Google SecOps@GoogleSecOps
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Google SecOps Detection Rules
2 years ago
0041
This rule detects DNS queries to domains that have been created within the last 30 days. This behavior can be indicative of newly registered malicious domains used for command and control, phishing, or other adversarial activities. The rule correlates DNS query events with WHOIS data to identify the domain creation time.
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Google SecOps@GoogleSecOps
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Google SecOps Detection Rules
2 years ago
0041
This rule detects a suspicious sequence of events: a process launching with a low prevalence executable (meaning it's rarely seen in the environment) followed by that same process initiating an HTTP connection to a low prevalence domain (a domain rarely accessed in the environment) within a 10-minute window. This combination can indicate the execution of novel or custom malware attempting to establish command and control or exfiltrate data to an unusual destination.
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Google SecOps@GoogleSecOps
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Google SecOps Detection Rules
2 years ago
0041
This rule detects when an Amazon EC2 instance or a container attempts to communicate with a black hole IP address, as reported by AWS GuardDuty. Black hole IP addresses are typically used to sinkhole malicious traffic or are unroutable, indicating potentially suspicious or misconfigured outbound communication from a compromised or misbehaving resource.
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Google SecOps@GoogleSecOps
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Google SecOps Detection Rules
2 years ago
0040
This rule identifies outbound network connections to a specific Autonomous System Number (ASN). The rule is designed to detect suspicious network traffic that might indicate command and control activity, data exfiltration, or other malicious communications originating from the monitored environment to an ASN that has been deemed suspicious. The specific ASN to monitor is configured within the rule.
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Google SecOps@GoogleSecOps
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Google SecOps Detection Rules
2 years ago
0037
This rule detects DNS queries for domains that contain a specific string (e.g., a company name) and are not registered with an approved domain registrar. It leverages WHOIS data to identify potentially malicious typosquatting domains that have been recently registered or observed. The rule specifically looks for DNS queries where the domain name matches a defined pattern (e.g., 'threatpunter') and the WHOIS information indicates a registrar other than the approved one ('MarkMonitor Inc.'). Additionally, it checks if the domain was first seen in the environment within the last 30 days, indicating a new or suspicious registration.
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Google SecOps@GoogleSecOps
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Google SecOps Detection Rules
2 years ago
0037
This rule detects when Amazon GuardDuty identifies an Amazon EC2 instance or a container querying algorithmically generated domains (DGA). DGA activity is often indicative of malware attempting to establish command and control (C2) communication with its operators. The rule specifically looks for GuardDuty findings with the product event type 'DGADomainRequest' and filters out sample findings.
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Google SecOps@GoogleSecOps
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Google SecOps Detection Rules
2 years ago
0036
This rule detects DNS queries for domains that have a very low rolling maximum prevalence (3 or less over a 10-day period). This can indicate newly registered domains, domains used for command and control, or other suspicious activity that has not yet gained widespread legitimate use. The rule correlates DNS events with derived prevalence data to identify these low-prevalence domains.
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Google SecOps@GoogleSecOps
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Google SecOps Detection Rules
2 years ago
1035
This rule detects activity associated with the Tor network within an AWS account, as identified by AWS GuardDuty. It specifically looks for GuardDuty findings related to TorIPCaller, TorRelay, or TorClient, indicating potential use of Tor for anonymization or command and control.
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Google SecOps@GoogleSecOps
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Google SecOps Detection Rules
2 years ago
0034
This rule identifies outbound network connections where the destination IP address is geo-located to a specific country, which is configured as 'France' in this instance. It can be adapted to monitor traffic to any country of interest. The rule itself does not specify malicious behavior but flags network communication to a particular geographic region. This could be indicative of potential data exfiltration, command and control (C2) communication, or unauthorized access attempts if the country is considered high-risk or unusual for the organization's normal operations.
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Google SecOps@GoogleSecOps
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Google SecOps Detection Rules
2 years ago
1034
This rule detects Command and Control (C2) activity identified by AWS GuardDuty across Amazon EC2, AWS Lambda, or Amazon EKS Runtimes. It specifically looks for GuardDuty findings with a product event type matching 'C&CActivity' and filters out sample findings. The rule aims to alert on suspicious communication patterns that indicate an adversary is controlling compromised resources within the AWS environment.
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Google SecOps@GoogleSecOps
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Google SecOps Detection Rules
2 years ago
0033
Detects file modifications to the temporary XML user database file in the ScreenConnect server. This activity can indicate local user modification, potentially as part of the exploitation of the ScreenConnect Authentication Bypass vulnerability (CVE-2024-1709) in versions <23.9.8. It may also be observed during legitimate modifications to local users or permissions within ScreenConnect.
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SigmaHQ Detections@sigmaHQ
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SigmaHQ
2 years ago
0025
This rule detects file modifications to the temporary XML user database file within the ScreenConnect server. Such modifications can indicate local user changes, which may occur during the exploitation of the ScreenConnect Authentication Bypass vulnerability (CVE-2024-1709) in versions prior to 23.9.8. Legitimate modifications to local users or permissions within ScreenConnect can also trigger this detection. This rule requires Advanced Auditing to log successful Windows Event ID 4663 events and a System Access Control List (SACL) set on the relevant ScreenConnect directory.
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SigmaHQ Detections@sigmaHQ
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SigmaHQ
2 years ago
0021
Identify network traffic based on a specific ASN
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Google SecOps@GoogleSecOps
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Google SecOps Detection Rules
2 years ago
003
Detects suspicious user agent strings commonly used by exploit and penetration testing frameworks such as Metasploit, Cobalt Strike, Empire, and Havoc. These user agents often mimic legitimate browsers or applications but contain specific patterns that indicate their use by these tools. The rule is designed to identify command and control (C2) communication or initial access attempts originating from these frameworks by analyzing proxy logs.
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SigmaHQ Detections@sigmaHQ
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SigmaHQ
2 years ago
3053
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