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Change logs for security intelligence update version 1.455.256.0

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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Released on

7/21/2026 4:36:17 PM

Added threat detections

Name Severity
Adware:Win32/Clover high
Behavior:Linux/SuspiciousWebServerActivity.C severe
Trojan:JS/Obfuse.ACE!MTB severe
Trojan:JS/PolinRider.C!MTB severe
Trojan:JS/PolinRider.CA!MTB severe
Trojan:MacOS/Infostealer.K severe
Trojan:MacOS/SuspCommandExec.B severe
Trojan:MacOS/SuspMalScript.E severe
Trojan:MSIL/Heracles.ABHC!MTB severe
Trojan:MSIL/Heracles.PYT!MTB severe
Trojan:MSIL/NanoCore.PAA!MTB severe
Trojan:MSIL/NanoCore.PAB!MTB severe
Trojan:Script/SvgStealer.ACU!MTB severe
Trojan:VBS/GuLoader.SQP!MTB severe
Trojan:Win32/Coins.MK!MTB severe
Trojan:Win32/DllHijack.SX!MTB severe
Trojan:Win32/KillAV.MK!MTB severe
Trojan:Win64/Androm.ABAN!MTB severe
Trojan:Win64/Midie.NYD!MTB severe
Trojan:Win64/Mikey.SXM!MTB severe
Trojan:Win64/Zusy.MKH!MTB severe
VirTool:Script/AmsiSuspClickfix.I severe
VirTool:Script/SuspSchedTask.H severe
VulnerableDriver:Win64/KillProc!AMTB severe

Updated threat detections

Name Severity
Backdoor:Linux/Mirai!rfn severe
Backdoor:MSIL/AsyncRat.AD!MTB severe
Backdoor:Win32/Rescoms!rfn severe
Backdoor:Win64/Coroxy!rfn severe
Behavior:Linux/SuspiciousWebServerActivity.A severe
Behavior:Linux/SuspiciousWebServerActivity.B severe
BrowserModifier:Win32/MediaArena high
Exploit:Win32/Tudimons.A!dha severe
HackTool:BAT/AutoKMS!AMTB high
HackTool:Python/Impacket!AMTB high
HackTool:Python/Multiverze!rfn high
HackTool:Win32/Keygen!MTB high
HackTool:Win32/Netpass high
HackTool:Win32/Passview high
HackTool:Win32/Patcher high
HackTool:Win64/CobaltStrike!rfn high
Program:Python/Multiverze!rfn high
PWS:MSIL/Stealer!rfn severe
PWS:Win32/Fareit!rfn severe
Ransom:MSIL/Filecoder!rfn severe
Ransom:Win32/Basta!rfn severe
Ransom:Win32/BlackCat!rfn severe
Ransom:Win64/Akira!rfn severe
Ransom:Win64/Babuk!rfn severe
Ransom:Win64/Filecoder!rfn severe
Ransom:Win64/NightSpire!rfn severe
SupportScam:Win32/Screcwon!AMTB severe
Tool:Python/Multiverze!rfn moderate
Trojan:AndroidOS/AVerseFalc!rfn severe
Trojan:BAT/LNK_DarkGate!rfn severe
Trojan:BAT/Qakbot!rfn severe
Trojan:HTML/Boxter.PGHT!MTB severe
Trojan:HTML/Phish!MSR severe
Trojan:JS/QakbotLNK!rfn severe
Trojan:JS/QuietVault!MTB severe
Trojan:Linux/Multiverze!rfn severe
Trojan:MacOS/Infostealer.J severe
Trojan:MacOS/Stealer!MTB severe
Trojan:MSIL/Gcleaner!MSR severe
Trojan:MSIL/Midie.SXD!MTB severe
Trojan:O97M/DDownloader!rfn severe
Trojan:PDF/Ursnif.RV!MTB severe
Trojan:PowerShell/Agent!AMTB severe
Trojan:PowerShell/Nophid!rfn severe
Trojan:PowerShell/Obfuse.PAD!MTB severe
Trojan:PowerShell/QakBot!rfn severe
Trojan:Script/Multiverze!rfn severe
Trojan:VBS/Emotet!rfn severe
Trojan:VBS/GuLoader.SNY!MTB severe
Trojan:VBS/Obfuse!rfn severe
Trojan:Win32/BadJoke!rfn severe
Trojan:Win32/Carbanak!rfn severe
Trojan:Win32/Casdet!rfn severe
Trojan:Win32/Ceevee severe
Trojan:Win32/CryptInject!rfn severe
Trojan:Win32/DllInject!rfn severe
Trojan:Win32/Egairtigado!rfn severe
Trojan:Win32/Emotet!rfn severe
Trojan:Win32/FormBook!rfn severe
Trojan:Win32/GenCBL!rfn severe
Trojan:Win32/IcedIDLNK!rfn severe
Trojan:Win32/Kepavll!rfn severe
Trojan:Win32/KoiLoader!rfn severe
Trojan:Win32/Leonem!rfn severe
Trojan:Win32/Malex!rfn severe
Trojan:Win32/Malgent severe
Trojan:Win32/Malgent!MSR severe
Trojan:Win32/MereTam!rfn severe
Trojan:Win32/Neoreblamy.NYL!MTB severe
Trojan:Win32/njRAT!rfn severe
Trojan:Win32/Noobyprotect severe
Trojan:Win32/PlugX.psyP!MTB severe
Trojan:Win32/Pomal!rfn severe
Trojan:Win32/Qakbot!rfn severe
Trojan:Win32/Qwexlafiba!rfn severe
Trojan:Win32/Ravartar!rfn severe
Trojan:Win32/Runner.HB!MTB severe
Trojan:Win32/Seheq!rfn severe
Trojan:Win32/ShortSeek!rfn severe
Trojan:Win32/Suschil!rfn severe
Trojan:Win32/SystemBC!rfn severe
Trojan:Win32/Tenga!MSR severe
Trojan:Win32/TurtleLoader!rfn severe
Trojan:Win32/WinLNK!rfn severe
Trojan:Win32/Yomal!rfn severe
Trojan:Win64/CobaltStrike!rfn severe
Trojan:Win64/CoinMiner!rfn severe
Trojan:Win64/CryptInject!rfn severe
Trojan:Win64/IcedID!rfn severe
Trojan:Win64/Jaik!MTB severe
Trojan:Win64/Qakbot!rfn severe
Trojan:Win64/ReflectiveLoader severe
Trojan:Win64/WinGoObfusc!rfn severe
Trojan:Win64/Zusy.AZU!MTB severe
TrojanDownloader:JS/Qakbot!rfn severe
TrojanDownloader:O97M/Emotet!rfn severe
TrojanDownloader:O97M/IcedID!rfn severe
TrojanDownloader:PDF/BumbleBee!rfn severe
TrojanDownloader:PDF/Gozi!rfn severe
TrojanDownloader:PowerShell/PEDropper!rfn severe
VirTool:MSIL/Subti!rfn severe
VirTool:Win64/Shelcorid!rfn severe