rule win_chches_auto {

    meta:
        author = "Felix Bilstein - yara-signator at cocacoding dot com"
        date = "2023-07-11"
        version = "1"
        description = "Detects win.chches."
        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.chches"
        malpedia_rule_date = "20230705"
        malpedia_hash = "42d0574f4405bd7d2b154d321d345acb18834a41"
        malpedia_version = "20230715"
        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 = { 81c61d051101 897de8 897df4 897df0 397d0c 7509 33c0 }
            // n = 7, score = 200
            //   81c61d051101         | add                 esi, 0x111051d
            //   897de8               | mov                 dword ptr [ebp - 0x18], edi
            //   897df4               | mov                 dword ptr [ebp - 0xc], edi
            //   897df0               | mov                 dword ptr [ebp - 0x10], edi
            //   397d0c               | cmp                 dword ptr [ebp + 0xc], edi
            //   7509                 | jne                 0xb
            //   33c0                 | xor                 eax, eax

        $sequence_1 = { 8d45b8 8b55f4 8b4e0c 53 52 8b5630 53 }
            // n = 7, score = 200
            //   8d45b8               | lea                 eax, [ebp - 0x48]
            //   8b55f4               | mov                 edx, dword ptr [ebp - 0xc]
            //   8b4e0c               | mov                 ecx, dword ptr [esi + 0xc]
            //   53                   | push                ebx
            //   52                   | push                edx
            //   8b5630               | mov                 edx, dword ptr [esi + 0x30]
            //   53                   | push                ebx

        $sequence_2 = { 8903 8b4534 83c408 85c0 7402 8908 8b4538 }
            // n = 7, score = 200
            //   8903                 | mov                 dword ptr [ebx], eax
            //   8b4534               | mov                 eax, dword ptr [ebp + 0x34]
            //   83c408               | add                 esp, 8
            //   85c0                 | test                eax, eax
            //   7402                 | je                  4
            //   8908                 | mov                 dword ptr [eax], ecx
            //   8b4538               | mov                 eax, dword ptr [ebp + 0x38]

        $sequence_3 = { ffd1 8b13 897a08 8b03 83c010 3bc7 7418 }
            // n = 7, score = 200
            //   ffd1                 | call                ecx
            //   8b13                 | mov                 edx, dword ptr [ebx]
            //   897a08               | mov                 dword ptr [edx + 8], edi
            //   8b03                 | mov                 eax, dword ptr [ebx]
            //   83c010               | add                 eax, 0x10
            //   3bc7                 | cmp                 eax, edi
            //   7418                 | je                  0x1a

        $sequence_4 = { ebc0 8b9650010000 ffd2 50 8b86dc000000 83c70c 57 }
            // n = 7, score = 200
            //   ebc0                 | jmp                 0xffffffc2
            //   8b9650010000         | mov                 edx, dword ptr [esi + 0x150]
            //   ffd2                 | call                edx
            //   50                   | push                eax
            //   8b86dc000000         | mov                 eax, dword ptr [esi + 0xdc]
            //   83c70c               | add                 edi, 0xc
            //   57                   | push                edi

        $sequence_5 = { 746f 8b4e64 50 ffd1 8b543bfc 8b4a14 03c0 }
            // n = 7, score = 200
            //   746f                 | je                  0x71
            //   8b4e64               | mov                 ecx, dword ptr [esi + 0x64]
            //   50                   | push                eax
            //   ffd1                 | call                ecx
            //   8b543bfc             | mov                 edx, dword ptr [ebx + edi - 4]
            //   8b4a14               | mov                 ecx, dword ptr [edx + 0x14]
            //   03c0                 | add                 eax, eax

        $sequence_6 = { 8b4c90fc 8b490c 8b1f 894b0c 8b0f 83c110 0f8495000000 }
            // n = 7, score = 200
            //   8b4c90fc             | mov                 ecx, dword ptr [eax + edx*4 - 4]
            //   8b490c               | mov                 ecx, dword ptr [ecx + 0xc]
            //   8b1f                 | mov                 ebx, dword ptr [edi]
            //   894b0c               | mov                 dword ptr [ebx + 0xc], ecx
            //   8b0f                 | mov                 ecx, dword ptr [edi]
            //   83c110               | add                 ecx, 0x10
            //   0f8495000000         | je                  0x9b

        $sequence_7 = { eb3d 3b4608 753a 8b0e 03c0 894604 3bcb }
            // n = 7, score = 200
            //   eb3d                 | jmp                 0x3f
            //   3b4608               | cmp                 eax, dword ptr [esi + 8]
            //   753a                 | jne                 0x3c
            //   8b0e                 | mov                 ecx, dword ptr [esi]
            //   03c0                 | add                 eax, eax
            //   894604               | mov                 dword ptr [esi + 4], eax
            //   3bcb                 | cmp                 ecx, ebx

        $sequence_8 = { 41 3bca 7cd1 eb06 8b4010 8945fc }
            // n = 6, score = 200
            //   41                   | inc                 ecx
            //   3bca                 | cmp                 ecx, edx
            //   7cd1                 | jl                  0xffffffd3
            //   eb06                 | jmp                 8
            //   8b4010               | mov                 eax, dword ptr [eax + 0x10]
            //   8945fc               | mov                 dword ptr [ebp - 4], eax

        $sequence_9 = { 8b5310 51 50 8b8798010000 52 ffd0 }
            // n = 6, score = 200
            //   8b5310               | mov                 edx, dword ptr [ebx + 0x10]
            //   51                   | push                ecx
            //   50                   | push                eax
            //   8b8798010000         | mov                 eax, dword ptr [edi + 0x198]
            //   52                   | push                edx
            //   ffd0                 | call                eax

    condition:
        7 of them and filesize < 122880
}