Detections

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

21 detections

The following analytic detects the use of known suspicious SSL certificates in any observed event where the SSL_CertFingerprint field is present. It leverages Cisco Secure Firewall logs and compares the SSL certificate SHA1 fingerprint against a blacklist of certificates associated with malware distribution, command and control (C2) infrastructure, or phishing campaigns. This activity is significant as adversaries often reuse or self-sign certificates across malicious infrastructure, allowing defenders to track and detect encrypted sessions even when domains or IPs change. If confirmed malicious, this may indicate beaconing, malware download, or data exfiltration over TLS/SSL.
Splunk Security@SplunkSecurity
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Splunk Security Content
23 days ago
001
Detects network traffic involving TLS certificates or Server Name Indication (SNI) values that attempt to impersonate the Uzbekistan state railway authority (azure.uzrailwaystax.com). The rules also flag connections associated with certificates issued by 'TLC DV TLS CA' and known C2 infrastructure using the spoofed railway certificate.
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Ibrahim Saud@tektrix
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Detections.ai Community
1 month ago
006
Detects network traffic involving TLS certificates or Server Name Indication (SNI) values that attempt to impersonate the Uzbekistan state railway authority (azure.uzrailwaystax.com). The rules also flag connections associated with certificates issued by 'TLC DV TLS CA' and known C2 infrastructure using the spoofed railway certificate.
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Ibrahim Saud@tektrix
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Detections.ai Community
1 month ago
005
Detects network communication with infrastructure identified as SilkParasite command and control by matching specific TLS certificate subjects and SHA-256 fingerprints associated with SpiceRAT.
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Ibrahim Saud@tektrix
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Detections.ai Community
1 month ago
005
Detects network traffic involving TLS certificates that impersonate the Uzbekistan state railway authority, specifically using certificates issued by 'TLC DV TLS CA' or specific known malicious certificate fingerprints. This activity is attributed to the threat actor SilkParasite.
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Ibrahim Saud@tektrix
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Detections.ai Community
1 month ago
003
Detects network traffic attempting to impersonate the Uzbekistan railway authority via suspicious TLS certificates. The rules identify specific SNI domains, certificate subjects, and issuers associated with the 'SilkParasite' campaign, which uses Chinese state-affiliated certificate authorities to facilitate C2 communications.
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Ibrahim Saud@tektrix
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Detections.ai Community
1 month ago
002
Detects network communication associated with the SilkParasite campaign, specifically targeting TLS connections that use spoofed certificates impersonating azure.uzrailwaystax.com or communication with known SpiceRAT command-and-control server IP addresses.
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Ibrahim Saud@tektrix
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Detections.ai Community
1 month ago
002
Detects TLS connections using suspicious certificates identified as belonging to the SilkParasite threat actor. The rule monitors for specific certificate issuer strings paired with either malicious subject domain patterns (targeting Central Asian entities) or specific JA4X fingerprints associated with known malicious activity.
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Arnold Chan@slaz
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Midnight Slayer
1 month ago
002
Detects TLS connections where the certificate subject is 'azure.uzrailwaystax.com' and the issuer is 'TLC DV TLS CA', indicating potential impersonation of the Uzbekistan railway authority infrastructure, likely associated with SilkParasite activity.
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Ibrahim Saud@tektrix
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Detections.ai Community
1 month ago
001
Detects TLS connections using suspicious certificates identified as belonging to the SilkParasite threat actor. The rule monitors for specific certificate issuer strings paired with either malicious subject domain patterns (targeting Central Asian entities) or specific JA4X fingerprints associated with known malicious activity.
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Arnold Chan@slaz
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Detections.ai Community
1 month ago
001
Detects network activity, including DNS queries and TLS certificate usage, related to the impersonation of the Uzbekistan state railway authority through the domain 'uzrailwaystax.com' and associated SSL/TLS certificates.
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Ibrahim Saud@tektrix
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Detections.ai Community
1 month ago
000
Detects TLS connections using suspicious certificates identified as belonging to the SilkParasite threat actor. The rule monitors for specific certificate issuer strings paired with either malicious subject domain patterns (targeting Central Asian entities) or specific JA4X fingerprints associated with known malicious activity.
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Arnold Chan@slaz
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Detection & Hunting Community
1 month ago
000
Detects TLS connections using suspicious certificates identified as belonging to the SilkParasite threat actor. The rule monitors for specific certificate issuer strings paired with either malicious subject domain patterns (targeting Central Asian entities) or specific JA4X fingerprints associated with known malicious activity.
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Arnold Chan@slaz
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Hunters
1 month ago
000
This rule monitors TLS traffic for a specific combination of certificate issuer Common Name (CN) matching 'YE1' and Server Name Indication (SNI) hostnames using known disposable or high-risk top-level domains (TLDs). This behavior is associated with the IronToll campaign, often indicative of command-and-control communication or malicious infrastructure staging.
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Arnold Chan@slaz
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Detections.ai Community
2 months ago
002
This rule monitors TLS traffic for a specific combination of certificate issuer Common Name (CN) matching 'YE1' and Server Name Indication (SNI) hostnames using known disposable or high-risk top-level domains (TLDs). This behavior is associated with the IronToll campaign, often indicative of command-and-control communication or malicious infrastructure staging.
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Arnold Chan@slaz
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Detection & Hunting Community
2 months ago
001
This rule monitors TLS traffic for a specific combination of certificate issuer Common Name (CN) matching 'YE1' and Server Name Indication (SNI) hostnames using known disposable or high-risk top-level domains (TLDs). This behavior is associated with the IronToll campaign, often indicative of command-and-control communication or malicious infrastructure staging.
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Arnold Chan@slaz
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Midnight Slayer
2 months ago
001
This rule detects the use of a suspicious wildcard certificate in the TLS handshake where the certificate subject contains a wildcard character followed by a domain name with a specific pattern (6 to 12 alphanumeric characters) and a top-level domain (TLD) from a list associated with malicious activities (xyz, top, club, icu). This pattern is often observed in attack infrastructure, particularly for phishing or command and control (C2) servers, to make them appear more legitimate or to facilitate rapid domain generation. The rule specifically looks for '*.domain.tld' where 'domain' is 6-12 chars and 'tld' is one of the specified suspicious TLDs.
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Darshan Thummar@Mighty
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Detections.ai Community
5 months ago
007
This detection identifies outbound SSL connections where the certificate issuer or subject matches suspicious strings associated with PureRAT infrastructure.
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Kyaw Pyiyt Htet@MikoyanDee
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Detections.ai Community
1 year ago
13589
KQL Query from file: Check for Entra Legacy TLS Login
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Steven Lim@KQLWizard
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SlimKQL
1 year ago
6082
Search for the files that are using a compromised certificate associated with the Nobelium campaign.
You can remove the comments to:
1. get the list of devices where there is at least one file signed with the certificate
2. get the list of files signed with the certificate
3. get the list of files signed with the certificate group by Devices
Azure Sentinel@AzureSentinel
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AzureSentinel
1 year ago
0031
This analytic detects the use of known suspicious SSL certificates by comparing the SHA1 fingerprint from Cisco Secure Firewall logs against a blacklist. This is crucial for identifying malware distribution, C2 infrastructure, or phishing campaigns that reuse or self-sign certificates. Detection of such activity may indicate beaconing, malware download, or data exfiltration over TLS/SSL.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
5087