ZenTools extracts cooked packages (.uasset/.uexp) from the IoStore container files (.ucas/.utoc + .pak).

Works on UE5.1 and 5.2 and should support legacy 5.1 archives too.

ZenTools.exe ExtractPackages <ContainerFolderPath> <ExtractionDir> [-EncryptionKeys=<KeyFile>]

If your game has encrypted paks, you must provide a keys.json, in the following format:

{
  "KeyGUID1": "KeyHex1",
  "KeyGUID2": "KeyHex2"
}

Obviously if your game only has one encryption key, you only need to specify one entry.

Example:

ZenTools.exe ExtractPackages "D:\\SteamLibrary\\steamapps\\common\\somegame\\projectname\\Content\\Paks" "D:\\somegame\\Output" -EncryptionKeys="D:\\somegame\\keys.json"

Since the game in the above example needs an AES key, this is the following keys.json file:

{
  "00000000-0000-0000-0000-000000000000": "DEADBEEFCAFEDEADBEEFCAFEDEADBEEFCAFEDEADBEEFCAFEDEADBEEFCAFEDEAD"
}