Change logs for security intelligence update version 1.443.778.0

This page lists newly added and updated threat detections included in security intelligence updates for Microsoft Defender Antivirus and other Microsoft antimalware. If you don’t find the latest security intelligence update version in the selector below, please refresh this page or let us know us know through the feedback smiley.

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Security intelligence update version

Released on

1/21/2026 8:00:37 AM

Added threat detections

Name	Severity
Behavior:Linux/MasqKworker.B	severe
Behavior:Win32/SuspBrowserCredDiscovery.SB	severe
Phish:HTML/FakeLogin.PGV!MTB	severe
Ransom:PowerShell/Lockbit.A!MTB	severe
Trojan:HTML/Gumblar.A!AMTB	severe
Trojan:JS/Pegel.AA!AMTB	severe
Trojan:PowerShell/Remcos.A!AMTB	severe
Trojan:Win32/ClickFix.IJ!MTB	severe
Trojan:Win32/ClickFix.SIAA	severe
Trojan:Win32/ClickFix.SKJ	severe
Trojan:Win32/ClickFix.SZA	severe
Trojan:Win32/ClickFix.SZAA	severe
Trojan:Win32/GenRansom.STS	severe
Trojan:Win32/Powdow.HH!MTB	severe
Trojan:Win32/TurtleLoader.UM!dha	severe

Updated threat detections

Name	Severity
Behavior:Linux/MasqKworker.A	severe
Behavior:Win32/ASRUsbCopiedRenamed	severe
Behavior:Win32/BlockOfficeCreateExeContentTracking	severe
Behavior:Win32/GenRansom.SI!rsm	severe
Behavior:Win32/GenRansom.ST!rsm	severe
Behavior:Win32/GenRansom.STM!rsm	severe
Behavior:Win32/Ransomware!GenDT	severe
Behavior:Win32/ReactJSExploit.SA	severe
Behavior:Win32/VulDriverAsrTracking	severe
Trojan:HTML/Redirector.AA!AMTB	severe
Trojan:JS/Malgent!MSR	severe
Trojan:Win32/ClickFix.SF	severe
Trojan:Win32/MalInject.A	severe
Trojan:Win32/PersistInStartupDir.A	severe
Trojan:Win32/PersistInStartupDir.B	severe
Trojan:Win32/PersistInStartupDir.C	severe
Trojan:Win64/Malgent!MSR	severe
TrojanDownloader:O97M/Malgent!MSR	severe