rule win_webc2_yahoo_auto {

    meta:
        author = "Felix Bilstein - yara-signator at cocacoding dot com"
        date = "2026-05-04"
        version = "1"
        description = "Detects win.webc2_yahoo."
        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_yahoo"
        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 = { 8d85f4feffff ff75fc 50 ff15???????? }
            // n = 4, score = 100
            //   8d85f4feffff         | lea                 eax, [ebp - 0x10c]
            //   ff75fc               | push                dword ptr [ebp - 4]
            //   50                   | push                eax
            //   ff15????????         |                     

        $sequence_1 = { 8b742414 2bf7 8d840e14e75e00 8bfd 99 f7ff }
            // n = 6, score = 100
            //   8b742414             | mov                 esi, dword ptr [esp + 0x14]
            //   2bf7                 | sub                 esi, edi
            //   8d840e14e75e00       | lea                 eax, [esi + ecx + 0x5ee714]
            //   8bfd                 | mov                 edi, ebp
            //   99                   | cdq                 
            //   f7ff                 | idiv                edi

        $sequence_2 = { ff75f8 8d85e8fbffff 50 ffd7 59 8d85e8fbffff }
            // n = 6, score = 100
            //   ff75f8               | push                dword ptr [ebp - 8]
            //   8d85e8fbffff         | lea                 eax, [ebp - 0x418]
            //   50                   | push                eax
            //   ffd7                 | call                edi
            //   59                   | pop                 ecx
            //   8d85e8fbffff         | lea                 eax, [ebp - 0x418]

        $sequence_3 = { 53 0f8497feffff e8???????? 59 8d45fc }
            // n = 5, score = 100
            //   53                   | push                ebx
            //   0f8497feffff         | je                  0xfffffe9d
            //   e8????????           |                     
            //   59                   | pop                 ecx
            //   8d45fc               | lea                 eax, [ebp - 4]

        $sequence_4 = { 83ef38 0345e4 50 8d4580 68???????? 50 ff15???????? }
            // n = 7, score = 100
            //   83ef38               | sub                 edi, 0x38
            //   0345e4               | add                 eax, dword ptr [ebp - 0x1c]
            //   50                   | push                eax
            //   8d4580               | lea                 eax, [ebp - 0x80]
            //   68????????           |                     
            //   50                   | push                eax
            //   ff15????????         |                     

        $sequence_5 = { e8???????? 59 33db b8???????? 53 }
            // n = 5, score = 100
            //   e8????????           |                     
            //   59                   | pop                 ecx
            //   33db                 | xor                 ebx, ebx
            //   b8????????           |                     
            //   53                   | push                ebx

        $sequence_6 = { 50 8bcb ff7508 e8???????? 6a64 }
            // n = 5, score = 100
            //   50                   | push                eax
            //   8bcb                 | mov                 ecx, ebx
            //   ff7508               | push                dword ptr [ebp + 8]
            //   e8????????           |                     
            //   6a64                 | push                0x64

        $sequence_7 = { 53 89450c bb04110000 6a64 e8???????? }
            // n = 5, score = 100
            //   53                   | push                ebx
            //   89450c               | mov                 dword ptr [ebp + 0xc], eax
            //   bb04110000           | mov                 ebx, 0x1104
            //   6a64                 | push                0x64
            //   e8????????           |                     

        $sequence_8 = { ff15???????? 802000 68???????? 68???????? 8d85c8feffff 68???????? 50 }
            // n = 7, score = 100
            //   ff15????????         |                     
            //   802000               | and                 byte ptr [eax], 0
            //   68????????           |                     
            //   68????????           |                     
            //   8d85c8feffff         | lea                 eax, [ebp - 0x138]
            //   68????????           |                     
            //   50                   | push                eax

        $sequence_9 = { 8a1e 881a 8a17 8816 }
            // n = 4, score = 100
            //   8a1e                 | mov                 bl, byte ptr [esi]
            //   881a                 | mov                 byte ptr [edx], bl
            //   8a17                 | mov                 dl, byte ptr [edi]
            //   8816                 | mov                 byte ptr [esi], dl

    condition:
        7 of them and filesize < 8060928
}