hXOR Packer

hXOR Packer is a PE (Portable Executable) packer with Huffman Compression and Xor encryption.

The unpacker will decompress and decrypt the packed PE and execute it directly from memory without needing any hard disk space to execute.

Technique Identifier

U1418

Technique Tags

hxor packer

Evasion Categories

Packers

Detection Rules

rule SI_CRYPT_hXOR_Jan24 : Crypter {

    meta:
        version = "1.0"
        date = "2024-01-04"
        modified = "2024-01-18"
        status = "RELEASED"
        sharing = "TLP:CLEAR"
        source = "SECUINFRA Falcon Team"
        author = "Marius Genheimer @ Falcon Team"
        description = "Detects executables packed/encrypted with the hXOR-Packer open-source crypter."
        category = "TOOL"
        mitre_att = "T1027.002"
        actor_type = "CRIMEWARE"
        reference = "https://github.com/akuafif/hXOR-Packer"
        hash = "7712186f3e91573ea1bb0cc9f85d35915742b165f9e8ed3d3e795aa5e699230f"
        minimum_yara = "2.0.0"
        best_before = "2025-01-04"

    strings:
        //This rule has been validated for the compression, encryption and compression+encryption modes of hXOR

        //Signature to locate the payload
        $binSignature = {46 49 46 41} 

        //Strings likely to be removed in attempts to conceal crypter
        $s_1 = "hXOR Un-Packer by Afif, 2012"
        $s_2 = "C:\\Users\\sony\\Desktop\\Packer\\"
        $s_3 = "H:\\Libraries\\My Documents\\Dropbox\\Ngee Ann Poly\\Semester 5\\Packer"
        $s_4 = "Scanning for Sandboxie..."
        $s_5 = "Scanning for VMware..."
        $s_6 = "Executing from Memory >>>>"
        $s_7 = "Extracting >>>>"
        $s_8 = "Decompressing >>>>"
        $s_9 = "Decrypting >>>>"

        //Anti-Analysis
        $aa_1 = "SbieDll.dll"
        $aa_2 = "VMwareUser.exe"
        $aa_3 = "GetTickCount"
        $aa_4 = "CreateToolhelp32Snapshot"

    condition:
        uint16(0) == 0x5A4D
        and uint16(0x28) != 0x0000 //IMAGE_DOS_HEADER.e_res2[0] contains offset for payload
        and $binSignature in (200000..filesize)
        and for all of ($s_*): (# >= 0) //these strings are optional
        and 3 of ($aa_*)
}

Contributors

Additional Resources

External Links

The resources provided below are associated links that will give you even more detailed information and research on current evasion technique. It is important to note that, while these resources may be helpful, it is important to exercise caution when following external links. As always, be careful when clicking on links from unknown sources, as they may lead to malicious content.

GitHub - fscene8/hXOR-Packer: A PE (Portable Executable) packer with Huffman Compression and Xor encryption.

Created

June 20, 2022

Last Revised

January 4, 2024