Detections

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

837 detections

This rule monitors incoming emails by cross-referencing sender addresses against a hardcoded list of known malicious or suspicious email accounts. It associates these emails with any potential attachments to provide context for further investigation.
avatar
Ankit Mehta@Secvyn
avatar
Detection & Hunting Community
2 months ago
7013
This rule detects anomalous, high-volume file and email access events by a single user from a single IP address within the Microsoft 365 environment. The detection logic groups operations such as file downloads, file access, and mailbox item access, flagging instances where a user performs 100 or more such operations, which may indicate data exfiltration or compromised account activity.
avatar
Ibrahim Saud@tektrix
avatar
Detections.ai Community
1 month ago
002
Detects inbound emails impersonating IT support or helpdesk staff that utilize urgent pretexts related to passkey, MFA, or SSO updates. These lures are commonly used in phishing campaigns to direct users toward malicious authentication flows, such as AiTM or device-code phishing setups.
avatar
Ibrahim Saud@tektrix
avatar
Detections.ai Community
1 month ago
001
Detects incoming EXTERNAL emails containing subject lines indicative of meeting invitations or call records, which include external URLs pointing to non-standard or unverified cloud storage providers, combined with explicit remote-access/support solicitation language. Requiring the remote-access/support signal and excluding internal-to-internal mail narrows this to callback-phishing style lures rather than routine meeting correspondence.
avatar
Arnold Chan@slaz
Defender - KQL
1 month ago
002
Detects the creation of email inbox rules in Microsoft 365 where the rule name is exceptionally short ('.' or '..') and the rule performs potentially malicious actions such as forwarding, redirecting, or deleting incoming messages. This is a common technique used by attackers to hide malicious email activity or exfiltrate sensitive data from a compromised account.
avatar
Ankit Mehta@Secvyn
avatar
Detections.ai Community
2 months ago
205
This rule detects potentially unauthorized mailbox content exports within Microsoft 365, including the creation of mailbox export requests, PST-related compliance searches, and the downloading of exported search results. These activities are common precursors to data exfiltration.
avatar
Ali AlEnezi@site
avatar
Detections.ai Community
1 month ago
802
This rule monitors for various types of events (user logons, network connections, API audits, cloud app events, and email traffic) originating from a specific CIDR block (160.79.104.0/21), which is flagged as suspicious or unauthorized.
avatar
Arnold Chan@slaz
avatar
Hunters
2 months ago
405
This rule detects various event types (email, identity authentication, network connections, and cloud audit logs) originating from or interacting with the specific IP address range 160.79.104.0/22 to 160.79.111.0/22, which is associated with known malicious activity.
avatar
Arnold Chan@slaz
avatar
Midnight Slayer
2 months ago
005
This rule detects the creation or modification of inbox rules in Microsoft 365 that exhibit suspicious behaviors, such as hiding messages, deleting them, moving them, or automatically forwarding/redirecting them to external addresses. It also flags rules that contain finance-related keywords, often used in Business Email Compromise (BEC) campaigns.
avatar
Ibrahim Saud@tektrix
avatar
Detections.ai Community
1 month ago
000
Detects Microsoft 365 MailItemsAccessed events where the email subject or body contains finance-related keywords such as 'invoice', 'payment', 'bank details', or 'wire'. This activity may indicate malicious mailbox scanning or data collection, often associated with unauthorized access or automated enumeration tools like the ARToken Inbox Monitor.
avatar
Ibrahim Saud@tektrix
avatar
Detections.ai Community
1 month ago
000
Detects automated mailbox access operations such as 'MailItemsAccessed' or 'Search-Mailbox' that are filtered by specific, high-risk financial or Business Email Compromise (BEC) keywords in the email subject line. This behavior is indicative of an automated 'inbox-monitor' style attack, where a compromised OAuth token is used to systematically scrape mailboxes for sensitive financial data.
avatar
Ibrahim Saud@tektrix
avatar
Detections.ai Community
1 month ago
000
Audits Direct Send traffic against an approved-IP watchlist, flagging unauthenticated inbound mail spoofing an internal domain from an unrecognized source IP. Fixed: RecipientDomain/SenderFromDomain were referenced but never defined (would have errored at runtime); replaced with derived SenderDomain/RecipientDomain consistent with the sibling rules. Removed a noisy display-name-contains-domain OR-branch. Replaced an always-true-in-practice auth check (required every one of SPF/DKIM/DMARC to show literal "Pass", which fails for many legitimate senders that pass via alignment on only one protocol) with the same CompAuth/all-three-fail logic used elsewhere in this set.
avatar
Arnold Chan@slaz
avatar
Hunters
2 months ago
204
Detects potential Business Email Compromise (BEC) related to 'Phantom Deal' fraud. The rule identifies email threads where a user receives an urgent request for proof of payment (MT103/UETR) within 72 hours of an email discussion involving both wire transfer/payment keywords and M&A/deal context.
avatar
Arnold Chan@slaz
avatar
Hunters
2 months ago
004
Detects network activity and email headers associated with the DoppelBrand campaign. The rule monitors DNS queries for specific IOC domains (service-nowinc.com, domainlify.net) and inspects SMTP traffic for malicious MAIL FROM addresses and Reply-To headers targeting these domains.
avatar
Arnold Chan@slaz
avatar
Detections.ai Community
2 months ago
004
Detects successful post-delivery email remediation actions (such as ZAP, manual deletion, or moving to junk) performed on emails associated with the Operation DoppelBrand campaign, identified by specific sender domains (service-nowinc.com, domainlify.net) or suspicious invoice-fraud subject lines.
avatar
Arnold Chan@slaz
avatar
Detections.ai Community
2 months ago
004
Detects inbound emails from external domains containing keywords related to financial transactions or urgency in the subject line (specifically matching forwarded or reply formats) accompanied by PDF or HTML attachments. This heuristic approach attempts to identify potential business email compromise (BEC) or phishing lures mimicking invoices or approval requests in environments where raw email body content is unavailable.
avatar
Arnold Chan@slaz
avatar
Detections.ai Community
2 months ago
004
Detects anomalous access to sensitive Microsoft Graph API endpoints (messages, mailFolders, contacts) following a device-code authentication. The rule specifically flags activity from non-standard or generic client applications, which is a pattern often associated with post-compromise proxying or token abuse, such as the 'ARToken' technique.
avatar
Ibrahim Saud@tektrix
avatar
Detections.ai Community
1 month ago
000
This rule detects high-volume, burst-pattern email distribution associated with a 'New VM Received' subject line, originating from non-authorized or non-corporate domains. This behavior is indicative of potential mass phishing or spam campaigns mimicking automated voicemail notifications.
avatar
Arnold Chan@slaz
avatar
Detection & Hunting Community
1 month ago
000
This rule detects high-volume, burst-pattern email distribution associated with a 'New VM Received' subject line, originating from non-authorized or non-corporate domains. This behavior is indicative of potential mass phishing or spam campaigns mimicking automated voicemail notifications.
avatar
Arnold Chan@slaz
avatar
Midnight Slayer
1 month ago
000
This rule detects high-volume, burst-pattern email distribution associated with a 'New VM Received' subject line, originating from non-authorized or non-corporate domains. This behavior is indicative of potential mass phishing or spam campaigns mimicking automated voicemail notifications.
avatar
Arnold Chan@slaz
avatar
Detections.ai Community
1 month ago
000
This rule monitors incoming emails by cross-referencing sender addresses against a hardcoded list of known malicious or suspicious email accounts. It associates these emails with any potential attachments to provide context for further investigation.
avatar
Ankit Mehta@Secvyn
avatar
SlimKQL
2 months ago
208
Page 13 of 40