avatar

Arnold Chan

@slaz
Trusted contributorCompletionist
2 followers2,100 downloads4,383 copies51 likes26,122 views

7,555 detections

Detects DNS queries and TLS SNI traffic directed towards known phishing domains that mimic Brazilian financial and government portals, specifically targeting 'gerenciadorcaixa.digital', 'aapj.digital', and 'receitafederal.digital'.
avatar
Arnold Chan@slaz
avatar
Detections.ai Community
2 months ago
004
This rule detects sophisticated phishing lure pages impersonating DocuSign or NFe documentation. It specifically identifies pages that implement multi-layered anti-bot gating techniques, including detection of browser automation (navigator.webdriver), identification of headless browser artifacts (headless/HeadlessChrome), and the presence of interaction-wait fallback timers using addEventListener, all tied to specific malicious content indicators.
avatar
Arnold Chan@slaz
avatar
Midnight Slayer
2 months ago
004
Detects the download of ZIP files with filenames matching known phishing patterns associated with NFe (Nota Fiscal Eletrônica) campaigns, correlated with access to specific malicious or suspicious download URLs within a 15-minute window.
avatar
Arnold Chan@slaz
Defender - KQL
2 months ago
104
Detects the download of ZIP files with filenames matching known phishing patterns associated with NFe (Nota Fiscal Eletrônica) campaigns, correlated with access to specific malicious or suspicious download URLs within a 15-minute window.
avatar
Arnold Chan@slaz
avatar
Detections.ai Community
2 months ago
104
Detects the execution of known Windows update-related binaries (UpdateAssistant.exe or AppUpdateHelper.exe) from non-standard, suspicious locations within AppData directories. This behavior is indicative of masquerading, where an adversary attempts to blend in by using a legitimate process name from an unexpected path.
avatar
Arnold Chan@slaz
avatar
Detection & Hunting Community
2 months ago
204
This rule detects suspicious PowerShell execution that attempts to download files from the internet using the Invoke-WebRequest cmdlet. It specifically looks for PowerShell processes launched with hidden and execution policy bypass flags, coupled with specific hardcoded malicious URL patterns associated with a known campaign (NotaFiscal/nfe_valid_access_key_2026_secure).
avatar
Arnold Chan@slaz
avatar
Detection & Hunting Community
2 months ago
004
This rule detects behavior associated with Hidden Virtual Network Computing (HVNC) implants, which allow remote attackers to interact with a hidden desktop session on a compromised host. The rule specifically looks for processes that perform a sequence of sensitive Windows API calls—CreateDesktopA, SetThreadDesktop, BitBlt/GetDIBits (for screen capture), and SendInput (for input simulation)—when originating from suspicious, unsigned, or non-standard file paths, indicating potential malicious use rather than legitimate software.
avatar
Arnold Chan@slaz
avatar
Midnight Slayer
2 months ago
004
Detects a specific pattern of PowerShell execution involving the download of files from a remote endpoint using parameters associated with Brazilian tax documents (NotaFiscal) to the Desktop directory, followed by immediate execution. The rule looks for a combination of hidden window style, Invoke-WebRequest, specific URL parameters (dl.php, NFe identifiers), and subsequent Start-Process calls, which is indicative of malware dropper activity.
avatar
Arnold Chan@slaz
avatar
Detection & Hunting Community
2 months ago
004
Detects suspicious PowerShell execution initiated by explorer.exe containing encoded commands, correlated with concurrent activity in the Windows RunMRU registry key or execution of rundll32.exe referencing 'WindowsUpdate.log'. This pattern is frequently used to mask malicious activity and maintain stealth during fileless execution or persistence operations.
avatar
Arnold Chan@slaz
avatar
Midnight Slayer
2 months ago
104
Detects anomalous, non-interactive sign-in activity in Microsoft 365 that suggests session cookie replay (Pass-the-Cookie). The rule correlates successful, MFA-validated interactive sign-ins against subsequent, non-interactive sign-ins that lack MFA, occur from a different device and IP address within a short time window, and bypass standard interactive re-authentication.
avatar
Arnold Chan@slaz
Defender - KQL
2 months ago
204
Page 551 of 756