Change logs for security intelligence update version 1.449.236.0

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

4/22/2026 1:04:00 AM

Added threat detections

Name	Severity
Backdoor:Win32/Spyder.DA!MTB	severe
Backdoor:Win32/Spyder.DB!MTB	severe
Backdoor:Win32/Spyder.DC!MTB	severe
Behavior:Win32/COMHijacking.Z!MTB	severe
Behavior:Win32/COMHijacking.ZA!MTB	severe
Behavior:Win32/SuspNodeActivity.A	severe
Exploit:Win32/UnDfndAVKil.BB	severe
HackTool:Win32/Keygen.CRE!AMTB	high
Trojan:MacOS/AtomicStealer.K!AMTB	severe
Trojan:Win64/SuSEnigmaProtect!rfn	severe

Updated threat detections

Name	Severity
Backdoor:MSIL/AsyncRat.AD!MTB	severe
Backdoor:PHP/Dirtelti	severe
Behavior:Win32/CVE-2026-33829.ZA!MTB	severe
Behavior:Win32/Etherratz.Z!MTB	severe
Behavior:Win32/Etherratz.ZA!MTB	severe
Behavior:Win32/Etherratz.ZB!MTB	severe
Behavior:Win32/Etherratz.ZC!MTB	severe
Behavior:Win32/PSConsReadIex.Z!MTB	severe
BrowserModifier:Win32/Prifou	high
Exploit:O97M/CVE-2025-53770.DA!ams	severe
HackTool:Python/Impacket!MSR	high
HackTool:Win32/Crack!MTB	high
HackTool:Win32/Patcher!AMTB	high
HackTool:Win64/EDRSandblast!MSR	high
Misleading:Win32/Lodi	high
PWS:MSIL/Browsstl!rfn	severe
PWS:MSIL/Gruppw.A!dha	severe
Ransom:Win32/Basta!rfn	severe
Ransom:Win64/Akira!rfn	severe
Ransom:Win64/BlackByte!rfn	severe
SupportScam:Win32/Screcwon!AMTB	severe
Trojan:AndroidOS/AVerseFalc!rfn	severe
Trojan:AndroidOS/Multiverze!rfn	severe
Trojan:HTML/IcedID!rfn	severe
Trojan:HTML/Qakbot!rfn	severe
Trojan:JS/Obfuse!MSR	severe
Trojan:Linux/Multiverze!rfn	severe
Trojan:Linux/SAgnt!MSR	severe
Trojan:MSIL/Prynt!rfn	severe
Trojan:PowerShell/Fleisnam.E!MTB	severe
Trojan:PowerShell/Obfuse!MSR	severe
Trojan:PowerShell/QakBot!rfn	severe
Trojan:Script/Malgent!MSR	severe
Trojan:VBS/Obfus!rfn	severe
Trojan:VBS/Qakbot!rfn	severe
Trojan:VBS/SLoad!MTB	severe
Trojan:Win32/AutoitInject.C!MTB	severe
Trojan:Win32/Casdet!rfn	severe
Trojan:Win32/Delf.OKO!MTB	severe
Trojan:Win32/Egairtigado!rfn	severe
Trojan:Win32/Emotet.PED!MTB	severe
Trojan:Win32/ICLoader.RND!MTB	severe
Trojan:Win32/Kepavll!rfn	severe
Trojan:Win32/Leonem!rfn	severe
Trojan:Win32/LummaStealer	severe
Trojan:Win32/Malgent	severe
Trojan:Win32/Malgent!MSR	severe
Trojan:Win32/Malgent!rfn	severe
Trojan:Win32/MalLoader!rfn	severe
Trojan:Win32/NetWalker!AMTB	severe
Trojan:Win32/Qakbot!rfn	severe
Trojan:Win32/Qwexlafiba!rfn	severe
Trojan:Win32/Ravartar!rfn	severe
Trojan:Win32/Rugmi!rfn	severe
Trojan:Win32/Seheq!rfn	severe
Trojan:Win32/ShortSeek!rfn	severe
Trojan:Win32/Suschil!rfn	severe
Trojan:Win32/Tiggre!plock	severe
Trojan:Win32/Tnega!ml	severe
Trojan:Win32/Trickbot!rfn	severe
Trojan:Win32/WinLNK!MSR	severe
Trojan:Win32/WinLNK!rfn	severe
Trojan:Win32/Yomal!rfn	severe
Trojan:Win32/Znyonm!rfn	severe
Trojan:Win64/BumbleBee!rfn	severe
Trojan:Win64/CobaltStrike!rfn	severe
Trojan:Win64/CoinMiner!rfn	severe
Trojan:Win64/Donut!rfn	severe
Trojan:Win64/Emotetcrypt!rfn	severe
Trojan:Win64/EmotetPacker!rfn	severe
Trojan:Win64/Malgent!MSR	severe
Trojan:Win64/Maloder!rfn	severe
Trojan:Win64/Mikey!MTB	severe
Trojan:Win64/Remcos.ARE!MTB	severe
Trojan:Win64/Rootkit!rfn	severe
Trojan:Win64/SpyLoader!rfn	severe
Trojan:Win64/SuSEnigmaProtect!MTB	severe
TrojanDownloader:BAT/QakBotLoader!rfn	severe
TrojanDownloader:JS/Qakbot!rfn	severe
TrojanDownloader:O97M/Emotet!rfn	severe
TrojanDropper:Win64/Qakbot!rfn	severe
UwS:MSIL/Malgent!MSR	high
VirTool:Win32/Sliver!rfn	severe
VirTool:WinNT/Rootkitdrv!rfn	severe
Worm:Win32/Gamarue!rfn	severe