rule win_webc2_head_auto {

    meta:
        author = "Felix Bilstein - yara-signator at cocacoding dot com"
        date = "2026-05-04"
        version = "1"
        description = "Detects win.webc2_head."
        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.webc2_head"
        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 = { 8b442410 83c204 48 89542424 }
            // n = 4, score = 100
            //   8b442410             | mov                 eax, dword ptr [esp + 0x10]
            //   83c204               | add                 edx, 4
            //   48                   | dec                 eax
            //   89542424             | mov                 dword ptr [esp + 0x24], edx

        $sequence_1 = { 5e 5d 83c8ff 5b 81c4341c0000 }
            // n = 5, score = 100
            //   5e                   | pop                 esi
            //   5d                   | pop                 ebp
            //   83c8ff               | or                  eax, 0xffffffff
            //   5b                   | pop                 ebx
            //   81c4341c0000         | add                 esp, 0x1c34

        $sequence_2 = { 8a15???????? b910000000 be???????? 8d7c2428 f3a5 895c2410 88542410 }
            // n = 7, score = 100
            //   8a15????????         |                     
            //   b910000000           | mov                 ecx, 0x10
            //   be????????           |                     
            //   8d7c2428             | lea                 edi, [esp + 0x28]
            //   f3a5                 | rep movsd           dword ptr es:[edi], dword ptr [esi]
            //   895c2410             | mov                 dword ptr [esp + 0x10], ebx
            //   88542410             | mov                 byte ptr [esp + 0x10], dl

        $sequence_3 = { 7e2a b910000000 be???????? 8dbc2474010000 f3a5 c1ea10 }
            // n = 6, score = 100
            //   7e2a                 | jle                 0x2c
            //   b910000000           | mov                 ecx, 0x10
            //   be????????           |                     
            //   8dbc2474010000       | lea                 edi, [esp + 0x174]
            //   f3a5                 | rep movsd           dword ptr es:[edi], dword ptr [esi]
            //   c1ea10               | shr                 edx, 0x10

        $sequence_4 = { 8d7c2414 c1e902 f3a5 8bca 83e103 f3a4 8b542414 }
            // n = 7, score = 100
            //   8d7c2414             | lea                 edi, [esp + 0x14]
            //   c1e902               | shr                 ecx, 2
            //   f3a5                 | rep movsd           dword ptr es:[edi], dword ptr [esi]
            //   8bca                 | mov                 ecx, edx
            //   83e103               | and                 ecx, 3
            //   f3a4                 | rep movsb           byte ptr es:[edi], byte ptr [esi]
            //   8b542414             | mov                 edx, dword ptr [esp + 0x14]

        $sequence_5 = { 55 ff15???????? a3???????? eb19 }
            // n = 4, score = 100
            //   55                   | push                ebp
            //   ff15????????         |                     
            //   a3????????           |                     
            //   eb19                 | jmp                 0x1b

        $sequence_6 = { 49 894c241c 8d942444040000 8d41fd 89542420 }
            // n = 5, score = 100
            //   49                   | dec                 ecx
            //   894c241c             | mov                 dword ptr [esp + 0x1c], ecx
            //   8d942444040000       | lea                 edx, [esp + 0x444]
            //   8d41fd               | lea                 eax, [ecx - 3]
            //   89542420             | mov                 dword ptr [esp + 0x20], edx

        $sequence_7 = { 8d049500000000 8d0c52 89442410 894c2424 8b442420 8b00 8bc8 }
            // n = 7, score = 100
            //   8d049500000000       | lea                 eax, [edx*4]
            //   8d0c52               | lea                 ecx, [edx + edx*2]
            //   89442410             | mov                 dword ptr [esp + 0x10], eax
            //   894c2424             | mov                 dword ptr [esp + 0x24], ecx
            //   8b442420             | mov                 eax, dword ptr [esp + 0x20]
            //   8b00                 | mov                 eax, dword ptr [eax]
            //   8bc8                 | mov                 ecx, eax

        $sequence_8 = { f6c202 7410 8088????????20 8a9405ecfcffff ebe3 80a0e0b8400000 }
            // n = 6, score = 100
            //   f6c202               | test                dl, 2
            //   7410                 | je                  0x12
            //   8088????????20       |                     
            //   8a9405ecfcffff       | mov                 dl, byte ptr [ebp + eax - 0x314]
            //   ebe3                 | jmp                 0xffffffe5
            //   80a0e0b8400000       | and                 byte ptr [eax + 0x40b8e0], 0

        $sequence_9 = { 884502 7e2a b910000000 be???????? 8dbc2474010000 }
            // n = 5, score = 100
            //   884502               | mov                 byte ptr [ebp + 2], al
            //   7e2a                 | jle                 0x2c
            //   b910000000           | mov                 ecx, 0x10
            //   be????????           |                     
            //   8dbc2474010000       | lea                 edi, [esp + 0x174]

    condition:
        7 of them and filesize < 106496
}