rule win_chches_auto {

    meta:
        author = "Felix Bilstein - yara-signator at cocacoding dot com"
        date = "2023-01-25"
        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 = "20230124"
        malpedia_hash = "2ee0eebba83dce3d019a90519f2f972c0fcf9686"
        malpedia_version = "20230125"
        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 = { 6a08 ffd1 8b574c 50 ffd2 8b4d08 8b5618 }
            // n = 7, score = 200
            //   6a08                 | push                8
            //   ffd1                 | call                ecx
            //   8b574c               | mov                 edx, dword ptr [edi + 0x4c]
            //   50                   | push                eax
            //   ffd2                 | call                edx
            //   8b4d08               | mov                 ecx, dword ptr [ebp + 8]
            //   8b5618               | mov                 edx, dword ptr [esi + 0x18]

        $sequence_1 = { c745e82c000000 c7853cffffff22006e00 c78540ffffff65007400 c78544ffffff77006f00 c78548ffffff72006b00 c7854cffffff2e007000 c78550ffffff72006f00 }
            // n = 7, score = 200
            //   c745e82c000000       | mov                 dword ptr [ebp - 0x18], 0x2c
            //   c7853cffffff22006e00     | mov    dword ptr [ebp - 0xc4], 0x6e0022
            //   c78540ffffff65007400     | mov    dword ptr [ebp - 0xc0], 0x740065
            //   c78544ffffff77006f00     | mov    dword ptr [ebp - 0xbc], 0x6f0077
            //   c78548ffffff72006b00     | mov    dword ptr [ebp - 0xb8], 0x6b0072
            //   c7854cffffff2e007000     | mov    dword ptr [ebp - 0xb4], 0x70002e
            //   c78550ffffff72006f00     | mov    dword ptr [ebp - 0xb0], 0x6f0072

        $sequence_2 = { 8b5644 83c135 51 50 6a08 ffd2 50 }
            // n = 7, score = 200
            //   8b5644               | mov                 edx, dword ptr [esi + 0x44]
            //   83c135               | add                 ecx, 0x35
            //   51                   | push                ecx
            //   50                   | push                eax
            //   6a08                 | push                8
            //   ffd2                 | call                edx
            //   50                   | push                eax

        $sequence_3 = { 8bcf 894304 e8???????? 83c404 6a00 6a00 53 }
            // n = 7, score = 200
            //   8bcf                 | mov                 ecx, edi
            //   894304               | mov                 dword ptr [ebx + 4], eax
            //   e8????????           |                     
            //   83c404               | add                 esp, 4
            //   6a00                 | push                0
            //   6a00                 | push                0
            //   53                   | push                ebx

        $sequence_4 = { 52 8945fc 50 8b4768 ffd0 85f6 0f846e020000 }
            // n = 7, score = 200
            //   52                   | push                edx
            //   8945fc               | mov                 dword ptr [ebp - 4], eax
            //   50                   | push                eax
            //   8b4768               | mov                 eax, dword ptr [edi + 0x68]
            //   ffd0                 | call                eax
            //   85f6                 | test                esi, esi
            //   0f846e020000         | je                  0x274

        $sequence_5 = { e8???????? 8b4b08 89410c 8b5308 83c404 837a0c00 740d }
            // n = 7, score = 200
            //   e8????????           |                     
            //   8b4b08               | mov                 ecx, dword ptr [ebx + 8]
            //   89410c               | mov                 dword ptr [ecx + 0xc], eax
            //   8b5308               | mov                 edx, dword ptr [ebx + 8]
            //   83c404               | add                 esp, 4
            //   837a0c00             | cmp                 dword ptr [edx + 0xc], 0
            //   740d                 | je                  0xf

        $sequence_6 = { 52 50 6801000040 57 8901 8b86a4000000 53 }
            // n = 7, score = 200
            //   52                   | push                edx
            //   50                   | push                eax
            //   6801000040           | push                0x40000001
            //   57                   | push                edi
            //   8901                 | mov                 dword ptr [ecx], eax
            //   8b86a4000000         | mov                 eax, dword ptr [esi + 0xa4]
            //   53                   | push                ebx

        $sequence_7 = { 83c31c 3bdf 7415 8b03 3bc7 740f 8b4e44 }
            // n = 7, score = 200
            //   83c31c               | add                 ebx, 0x1c
            //   3bdf                 | cmp                 ebx, edi
            //   7415                 | je                  0x17
            //   8b03                 | mov                 eax, dword ptr [ebx]
            //   3bc7                 | cmp                 eax, edi
            //   740f                 | je                  0x11
            //   8b4e44               | mov                 ecx, dword ptr [esi + 0x44]

        $sequence_8 = { 85c0 751e 68c8000000 c787c800000032000000 8b4644 6a08 ffd0 }
            // n = 7, score = 200
            //   85c0                 | test                eax, eax
            //   751e                 | jne                 0x20
            //   68c8000000           | push                0xc8
            //   c787c800000032000000     | mov    dword ptr [edi + 0xc8], 0x32
            //   8b4644               | mov                 eax, dword ptr [esi + 0x44]
            //   6a08                 | push                8
            //   ffd0                 | call                eax

        $sequence_9 = { 8b464c ffd0 8b0f 8b54240c 894114 8b4204 }
            // n = 6, score = 200
            //   8b464c               | mov                 eax, dword ptr [esi + 0x4c]
            //   ffd0                 | call                eax
            //   8b0f                 | mov                 ecx, dword ptr [edi]
            //   8b54240c             | mov                 edx, dword ptr [esp + 0xc]
            //   894114               | mov                 dword ptr [ecx + 0x14], eax
            //   8b4204               | mov                 eax, dword ptr [edx + 4]

    condition:
        7 of them and filesize < 122880
}