rule win_zeroaccess_auto {

    meta:
        author = "Felix Bilstein - yara-signator at cocacoding dot com"
        date = "2021-06-10"
        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 = "20210604"
        malpedia_hash = "be09d5d71e77373c0f538068be31a2ad4c69cfbd"
        malpedia_version = "20210616"
        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 = 300
            //   85c0                 | test                eax, eax
            //   7408                 | je                  0xa
            //   ff15????????         |                     
            //   eb02                 | jmp                 4

        $sequence_1 = { eb02 33c0 8d65b8 5f 5e 5b }
            // n = 6, score = 200
            //   eb02                 | jmp                 4
            //   33c0                 | xor                 eax, eax
            //   8d65b8               | lea                 esp, dword ptr [ebp - 0x48]
            //   5f                   | pop                 edi
            //   5e                   | pop                 esi
            //   5b                   | pop                 ebx

        $sequence_2 = { ff15???????? 85c0 7407 b8e3030000 }
            // n = 4, score = 200
            //   ff15????????         |                     
            //   85c0                 | test                eax, eax
            //   7407                 | je                  9
            //   b8e3030000           | mov                 eax, 0x3e3

        $sequence_3 = { 68???????? 6a10 68???????? 68060000c8 ff7308 ff15???????? }
            // n = 6, score = 200
            //   68????????           |                     
            //   6a10                 | push                0x10
            //   68????????           |                     
            //   68060000c8           | push                0xc8000006
            //   ff7308               | push                dword ptr [ebx + 8]
            //   ff15????????         |                     

        $sequence_4 = { 48 83c9ff c744242804000000 48 }
            // n = 4, score = 200
            //   48                   | dec                 eax
            //   83c9ff               | or                  ecx, 0xffffffff
            //   c744242804000000     | mov                 dword ptr [esp + 0x28], 4
            //   48                   | dec                 eax

        $sequence_5 = { 3bc1 7604 83c8ff c3 }
            // n = 4, score = 200
            //   3bc1                 | cmp                 eax, ecx
            //   7604                 | jbe                 6
            //   83c8ff               | or                  eax, 0xffffffff
            //   c3                   | ret                 

        $sequence_6 = { 8b45fc 3bf8 730e 2bc7 }
            // n = 4, score = 200
            //   8b45fc               | mov                 eax, dword ptr [ebp - 4]
            //   3bf8                 | cmp                 edi, eax
            //   730e                 | jae                 0x10
            //   2bc7                 | sub                 eax, edi

        $sequence_7 = { 6a01 8d45f4 50 ff7308 ff15???????? 85c0 7408 }
            // n = 7, score = 200
            //   6a01                 | push                1
            //   8d45f4               | lea                 eax, dword ptr [ebp - 0xc]
            //   50                   | push                eax
            //   ff7308               | push                dword ptr [ebx + 8]
            //   ff15????????         |                     
            //   85c0                 | test                eax, eax
            //   7408                 | je                  0xa

        $sequence_8 = { ff15???????? 6a01 8d45f8 50 57 ff15???????? }
            // n = 6, score = 200
            //   ff15????????         |                     
            //   6a01                 | push                1
            //   8d45f8               | lea                 eax, dword ptr [ebp - 8]
            //   50                   | push                eax
            //   57                   | push                edi
            //   ff15????????         |                     

        $sequence_9 = { 57 6a02 68???????? ff75f8 ff15???????? }
            // n = 5, score = 200
            //   57                   | push                edi
            //   6a02                 | push                2
            //   68????????           |                     
            //   ff75f8               | push                dword ptr [ebp - 8]
            //   ff15????????         |                     

        $sequence_10 = { 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_11 = { 44 8d48b5 ba03001f00 66890437 }
            // n = 4, score = 100
            //   44                   | inc                 esp
            //   8d48b5               | lea                 ecx, dword ptr [eax - 0x4b]
            //   ba03001f00           | mov                 edx, 0x1f0003
            //   66890437             | mov                 word ptr [edi + esi], ax

        $sequence_12 = { c1ea0e 3bc2 7716 ba00800000 45 33c0 }
            // n = 6, score = 100
            //   c1ea0e               | shr                 edx, 0xe
            //   3bc2                 | cmp                 eax, edx
            //   7716                 | ja                  0x18
            //   ba00800000           | mov                 edx, 0x8000
            //   45                   | inc                 ebp
            //   33c0                 | xor                 eax, eax

        $sequence_13 = { 8d4558 48 8bf1 48 894df0 49 83cfff }
            // n = 7, score = 100
            //   8d4558               | lea                 eax, dword ptr [ebp + 0x58]
            //   48                   | dec                 eax
            //   8bf1                 | mov                 esi, ecx
            //   48                   | dec                 eax
            //   894df0               | mov                 dword ptr [ebp - 0x10], ecx
            //   49                   | dec                 ecx
            //   83cfff               | or                  edi, 0xffffffff

    condition:
        7 of them and filesize < 172032
}