rule win_zeroaccess_auto {

    meta:
        author = "Felix Bilstein - yara-signator at cocacoding dot com"
        date = "2026-05-04"
        version = "1"
        description = "Detects win.zeroaccess."
        info = "autogenerated rule brought to you by yara-signator"
        tool = "yara-signator v0.6.0"
        signator_config = "callsandjumps;datarefs;binvalue"
        malpedia_reference = "https://malpedia.caad.fkie.fraunhofer.de/details/win.zeroaccess"
        malpedia_rule_date = "20260422"
        malpedia_hash = "a182e35da64e6d71cb55f125c4d4225196523f14"
        malpedia_version = "20260504"
        malpedia_license = "CC BY-SA 4.0"
        malpedia_sharing = "TLP:WHITE"

    /* DISCLAIMER
     * The strings used in this rule have been automatically selected from the
     * disassembly of memory dumps and unpacked files, using YARA-Signator.
     * The code and documentation is published here:
     * https://github.com/fxb-cocacoding/yara-signator
     * As Malpedia is used as data source, please note that for a given
     * number of families, only single samples are documented.
     * This likely impacts the degree of generalization these rules will offer.
     * Take the described generation method also into consideration when you
     * apply the rules in your use cases and assign them confidence levels.
     */


    strings:
        $sequence_0 = { 85c0 7408 ff15???????? eb02 }
            // n = 4, score = 400
            //   85c0                 | test                eax, eax
            //   7408                 | je                  0xa
            //   ff15????????         |                     
            //   eb02                 | jmp                 4

        $sequence_1 = { 56 68???????? 50 8d460c 50 }
            // n = 5, score = 300
            //   56                   | push                esi
            //   68????????           |                     
            //   50                   | push                eax
            //   8d460c               | lea                 eax, [esi + 0xc]
            //   50                   | push                eax

        $sequence_2 = { 6a01 8d45f4 50 ff7308 ff15???????? 85c0 7408 }
            // n = 7, score = 300
            //   6a01                 | push                1
            //   8d45f4               | lea                 eax, [ebp - 0xc]
            //   50                   | push                eax
            //   ff7308               | push                dword ptr [ebx + 8]
            //   ff15????????         |                     
            //   85c0                 | test                eax, eax
            //   7408                 | je                  0xa

        $sequence_3 = { 33c0 48 83c9ff c744242804000000 48 }
            // n = 5, score = 300
            //   33c0                 | xor                 eax, eax
            //   48                   | dec                 eax
            //   83c9ff               | or                  ecx, 0xffffffff
            //   c744242804000000     | mov                 dword ptr [esp + 0x28], 4
            //   48                   | dec                 eax

        $sequence_4 = { 56 6a10 8945e8 8d45e4 50 }
            // n = 5, score = 300
            //   56                   | push                esi
            //   6a10                 | push                0x10
            //   8945e8               | mov                 dword ptr [ebp - 0x18], eax
            //   8d45e4               | lea                 eax, [ebp - 0x1c]
            //   50                   | push                eax

        $sequence_5 = { 68???????? 68060000c8 ff7708 ff15???????? 85c0 }
            // n = 5, score = 300
            //   68????????           |                     
            //   68060000c8           | push                0xc8000006
            //   ff7708               | push                dword ptr [edi + 8]
            //   ff15????????         |                     
            //   85c0                 | test                eax, eax

        $sequence_6 = { 50 68???????? 6889001200 8d45fc }
            // n = 4, score = 300
            //   50                   | push                eax
            //   68????????           |                     
            //   6889001200           | push                0x120089
            //   8d45fc               | lea                 eax, [ebp - 4]

        $sequence_7 = { 68???????? 68060000c8 ff7308 ff15???????? }
            // n = 4, score = 300
            //   68????????           |                     
            //   68060000c8           | push                0xc8000006
            //   ff7308               | push                dword ptr [ebx + 8]
            //   ff15????????         |                     

        $sequence_8 = { 740c bf03000040 eb05 bf010000c0 85ff }
            // n = 5, score = 200
            //   740c                 | je                  0xe
            //   bf03000040           | mov                 edi, 0x40000003
            //   eb05                 | jmp                 7
            //   bf010000c0           | mov                 edi, 0xc0000001
            //   85ff                 | test                edi, edi

        $sequence_9 = { 3bc1 7604 83c8ff c3 }
            // n = 4, score = 200
            //   3bc1                 | cmp                 eax, ecx
            //   7604                 | jbe                 6
            //   83c8ff               | or                  eax, 0xffffffff
            //   c3                   | ret                 

        $sequence_10 = { ff15???????? 85c0 7407 b8e3030000 }
            // n = 4, score = 200
            //   ff15????????         |                     
            //   85c0                 | test                eax, eax
            //   7407                 | je                  9
            //   b8e3030000           | mov                 eax, 0x3e3

        $sequence_11 = { 7e29 41 8d5001 41 8bc0 }
            // n = 5, score = 100
            //   7e29                 | jle                 0x2b
            //   41                   | inc                 ecx
            //   8d5001               | lea                 edx, [eax + 1]
            //   41                   | inc                 ecx
            //   8bc0                 | mov                 eax, eax

        $sequence_12 = { 85c0 753d 8175bb01010101 48 8d4de7 }
            // n = 5, score = 100
            //   85c0                 | test                eax, eax
            //   753d                 | jne                 0x3f
            //   8175bb01010101       | xor                 dword ptr [ebp - 0x45], 0x1010101
            //   48                   | dec                 eax
            //   8d4de7               | lea                 ecx, [ebp - 0x19]

        $sequence_13 = { fec1 45 0fb6c1 47 021418 43 }
            // n = 6, score = 100
            //   fec1                 | inc                 cl
            //   45                   | inc                 ebp
            //   0fb6c1               | movzx               eax, cl
            //   47                   | inc                 edi
            //   021418               | add                 dl, byte ptr [eax + ebx]
            //   43                   | inc                 ebx

    condition:
        7 of them and filesize < 464896
}