If you updated The Sims 4 on July 21 and Windows Defender immediately quarantined your game, you are not alone and your PC is not infected. A missing digital signature on the launcher executable is triggering false virus warnings for players on both Steam and the EA App.
What is happening
The July 21 patch (version 1.126.58.1030), which introduced autosave and Memory Boost on consoles, shipped with a launcher file (TS4_Launcher_x64.exe) that lost its digital signature. Without that signature, Windows Defender identifies the file as Trojan/Phonzy.A!ml and quarantines it on sight.
Players on the EA Forums describe an endless loop: Defender removes the file, Steam or the EA App verifies and re-downloads it, and Defender immediately flags it again. Repairing, reinstalling, and clearing caches do not resolve the issue because the replacement file is the same unsigned build.
The main game executable (TS4_x64.exe) is unaffected. Only the launcher is flagged.
The Sims Team's response
The Sims Team acknowledged the problem within roughly a day, posting across the EA Forums, the official Sims Discord, and Sims Direct social accounts. Their statement confirms a digital signature fix is in progress and should arrive "in the coming days." Because the fix only touches the launcher, it will not change the game version number and will have no impact on installed mods.
The team also flagged a separate issue discovered alongside this update: a save-override bug where exiting an autosave with "Save and exit" can overwrite a different manual save under specific conditions. A fix for that is being worked on separately.
Should you disable your antivirus?
No. Multiple players in the forum thread have pointed out that disabling Windows Defender or Smart App Control to force-launch the game is not a reasonable ask, and The Sims Team has not suggested doing so. The safest course is to wait for the signed launcher update.
If you are comfortable managing Windows Defender exclusions and understand the risks, some players have reported that adding the Sims 4 installation folder to Defender's exclusion list allows the game to launch. This is a temporary measure you would want to remove once the signed build arrives.
Protecting your saves in the meantime
Until the save-override bug is also patched, the team recommends:
- Always do a standard manual save before exiting a save file and loading an autosave, especially if you plan to load a different household next.
The launcher fix is not expected to require a full game update, so keep an eye on the EA App or Steam for a small download in the next few days.