Detections

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

1,605 detections

Detects DNS queries initiated by "QuickAssist.exe" to the Microsoft Quick Assist primary endpoint. This activity is often associated with social engineering attacks leading to ransomware, where threat actors misuse Quick Assist to gain remote access to a victim's system.
avatar
SigmaHQ Detections@sigmaHQ
avatar
SigmaHQ
1 year ago
0026
This rule detects when a known malicious file, identified by its SHA256 hash through VirusTotal relationships, attempts to contact a domain that VirusTotal also associates with that file. It correlates DNS query events with VirusTotal intelligence to identify suspicious network communications originating from potentially compromised systems.
avatar
Google SecOps@GoogleSecOps
avatar
Google SecOps Detection Rules
1 year ago
1039
This rule detects DNS queries to domains identified as Command and Control (C2) infrastructure within a Threat Intelligence (TI) feed, specifically MISP. It correlates DNS events with MISP data where the entity type is 'DOMAIN_NAME' and the threat summary indicates 'C2 domains'. The rule is designed to identify potential C2 communications from internal hosts.
avatar
Google SecOps@GoogleSecOps
avatar
Google SecOps Detection Rules
1 year ago
0036
Detects DNS queries to domains classified as 'Gaming Sites' within a MISP threat intelligence feed. This rule is designed to identify potential policy violations related to accessing unauthorized gaming websites.
avatar
Google SecOps@GoogleSecOps
avatar
Google SecOps Detection Rules
1 year ago
0031
Detects a DNS query by a non browser process on the system to "azurewebsites.net". The latter was often used by threat actors as a malware hosting and exfiltration site.
avatar
SigmaHQ Detections@sigmaHQ
avatar
SigmaHQ
1 year ago
000
Detects DNS queries to a TeamViewer domain only resolved by a TeamViewer client by an image that isn't named TeamViewer (sometimes used by threat actors for obfuscation)
avatar
SigmaHQ Detections@sigmaHQ
avatar
SigmaHQ
1 year ago
000
Detects DNS queries to domains commonly used by threat actors to host malware payloads or redirect through URL shorteners.
These include platforms like Cloudflare Workers, TryCloudflare, InfinityFree, and URL shorteners such as tinyurl and lihi.cc.
Such DNS activity can indicate potential delivery or command-and-control communication attempts.
avatar
SigmaHQ Detections@sigmaHQ
avatar
SigmaHQ
1 year ago
000
Detect DNS events that communicate with gaming sites in MISP. These violate policy.
avatar
Google SecOps@GoogleSecOps
avatar
Google SecOps Detection Rules
1 year ago
004
Detect DNS events that indicate communication to a C2 domain in MISP
avatar
Google SecOps@GoogleSecOps
avatar
Google SecOps Detection Rules
1 year ago
003
Detects DNS queries to domains associated with Katz Stealer malware. Katz Stealer is a malware variant that is known to be used for stealing sensitive information from compromised systems. In Enterprise environments, DNS queries to these domains may indicate potential malicious activity or compromise.
avatar
SigmaHQ Detections@sigmaHQ
avatar
SigmaHQ
1 year ago
0021
Detects DNS queries to domains associated with Katz Stealer malware. Katz Stealer is a malware variant known for stealing sensitive information. In enterprise environments, such DNS queries may indicate potential malicious activity or compromise.
avatar
SigmaHQ Detections@sigmaHQ
avatar
SigmaHQ
1 year ago
0018
Detects DNS queries initiated by "QuickAssist.exe" to Microsoft Quick Assist primary endpoint that is used to establish a session.
avatar
SigmaHQ Detections@sigmaHQ
avatar
SigmaHQ
1 year ago
001
Alert on known Hash querying a known hostname with VT Relationships
avatar
Google SecOps@GoogleSecOps
avatar
Google SecOps Detection Rules
1 year ago
002
Detects network enumeration commands as identified in CISA Living off the Land pdf. Alone they may be normal but in concert, they may be worth looking into
avatar
Google SecOps@GoogleSecOps
avatar
Google SecOps Detection Rules
1 year ago
001
Detects an attempt to leverage dnscmd.exe to enumerate DNS zones or records of a domain. This activity can be indicative of reconnaissance by an attacker.
avatar
SigmaHQ Detections@sigmaHQ
avatar
SigmaHQ
1 year ago
1021
The analytic identifies potential DNS exfiltration using the nslookup application. It detects specific command-line parameters such as query type (TXT, A, AAAA) and retry options, which are commonly used by attackers to exfiltrate data. The detection leverages Endpoint Detection and Response (EDR) telemetry, focusing on process execution logs. This activity is significant as it may indicate an attempt to communicate with a Command and Control (C2) server or exfiltrate sensitive data. If confirmed malicious, this could lead to data breaches and unauthorized access to critical information.
Splunk Security@SplunkSecurity
avatar
Splunk Security Content
1 year ago
1077
The following analytic identifies potential DNS data exfiltration using a pre-trained deep learning model. It leverages DNS request data from the Network Resolution datamodel and computes features from past events between the same source and domain. The model generates a probability score (pred_is_exfiltration_proba) indicating the likelihood of data exfiltration. This activity is significant as DNS tunneling can be used by attackers to covertly exfiltrate sensitive data. If confirmed malicious, this could lead to unauthorized data access and potential data breaches, compromising the organization's security posture.
Splunk Security@SplunkSecurity
avatar
Splunk Security Content
1 year ago
2064
This analytic detects the presence of SIGRed (CVE-2020-1350), a critical DNS vulnerability, using Zeek DNS and Zeek Conn data. It identifies specific DNS query types (SIG and KEY) and checks for high data transfer within a flow (over 65KB). This detection is significant because SIGRed allows attackers to execute remote code on Windows DNS servers, potentially leading to unauthorized access and control. If confirmed malicious, this activity could result in data exfiltration, service disruption, or further network compromise. Immediate investigation and mitigation, such as patching or isolating the affected server, are crucial.
Splunk Security@SplunkSecurity
avatar
Splunk Security Content
1 year ago
0063
This analytic identifies a large volume of DNS ANY queries, which may indicate a DNS amplification attack. It leverages the Network_Resolution data model to count DNS queries of type "ANY" directed to specific destinations. This activity is significant because DNS amplification attacks can overwhelm network resources, leading to Denial of Service (DoS) conditions. If confirmed malicious, this activity could disrupt services, degrade network performance, and potentially be part of a larger Distributed Denial of Service (DDoS) attack, impacting the availability of critical infrastructure.
Splunk Security@SplunkSecurity
avatar
Splunk Security Content
1 year ago
1047
This analytic detects excessive usage of the nslookup application, which may indicate potential DNS exfiltration attempts. It monitors process executions, specifically focusing on nslookup.exe, and identifies outliers by comparing the frequency of nslookup executions against a calculated threshold. This activity is significant as it can reveal attempts by malware or APT groups to exfiltrate data via DNS queries. If confirmed malicious, this behavior could allow attackers to stealthily transfer sensitive information out of the network, bypassing traditional data exfiltration defenses.
Splunk Security@SplunkSecurity
avatar
Splunk Security Content
1 year ago
0043
This analytic detects DNS queries to common Ngrok domains, indicating potential use of the Ngrok reverse proxy tool. It leverages the Network Resolution datamodel to identify queries to domains such as "*.ngrok.com" and "*.ngrok.io". While Ngrok usage is not inherently malicious, it has been increasingly adopted by adversaries for covert communication and data exfiltration. If confirmed malicious, this activity could allow attackers to bypass network defenses, establish persistent connections, and exfiltrate sensitive data, posing a significant threat to the network's security.
Splunk Security@SplunkSecurity
avatar
Splunk Security Content
1 year ago
0041
Page 73 of 77