rule win_webc2_yahoo_auto {

    meta:
        author = "Felix Bilstein - yara-signator at cocacoding dot com"
        date = "2023-03-28"
        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 = "20230328"
        malpedia_hash = "9d2d75cef573c1c2d861f5197df8f563b05a305d"
        malpedia_version = "20230407"
        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 = { 8b7708 83c418 3b770c 7377 8d8600010000 53 89450c }
            // n = 7, score = 100
            //   8b7708               | mov                 esi, dword ptr [edi + 8]
            //   83c418               | add                 esp, 0x18
            //   3b770c               | cmp                 esi, dword ptr [edi + 0xc]
            //   7377                 | jae                 0x79
            //   8d8600010000         | lea                 eax, [esi + 0x100]
            //   53                   | push                ebx
            //   89450c               | mov                 dword ptr [ebp + 0xc], eax

        $sequence_1 = { 69c010270000 03c8 4e 8bc1 99 f7fe 8b45f4 }
            // n = 7, score = 100
            //   69c010270000         | imul                eax, eax, 0x2710
            //   03c8                 | add                 ecx, eax
            //   4e                   | dec                 esi
            //   8bc1                 | mov                 eax, ecx
            //   99                   | cdq                 
            //   f7fe                 | idiv                esi
            //   8b45f4               | mov                 eax, dword ptr [ebp - 0xc]

        $sequence_2 = { 85c0 7403 50 ffd7 8bb694841e00 85f6 7403 }
            // n = 7, score = 100
            //   85c0                 | test                eax, eax
            //   7403                 | je                  5
            //   50                   | push                eax
            //   ffd7                 | call                edi
            //   8bb694841e00         | mov                 esi, dword ptr [esi + 0x1e8494]
            //   85f6                 | test                esi, esi
            //   7403                 | je                  5

        $sequence_3 = { 59 7637 8d0433 8945fc 56 e8???????? }
            // n = 6, score = 100
            //   59                   | pop                 ecx
            //   7637                 | jbe                 0x39
            //   8d0433               | lea                 eax, [ebx + esi]
            //   8945fc               | mov                 dword ptr [ebp - 4], eax
            //   56                   | push                esi
            //   e8????????           |                     

        $sequence_4 = { 53 56 ff750c ff15???????? 57 }
            // n = 5, score = 100
            //   53                   | push                ebx
            //   56                   | push                esi
            //   ff750c               | push                dword ptr [ebp + 0xc]
            //   ff15????????         |                     
            //   57                   | push                edi

        $sequence_5 = { 6a00 50 e8???????? 83c418 035dec }
            // n = 5, score = 100
            //   6a00                 | push                0
            //   50                   | push                eax
            //   e8????????           |                     
            //   83c418               | add                 esp, 0x18
            //   035dec               | add                 ebx, dword ptr [ebp - 0x14]

        $sequence_6 = { 57 898694841e00 e8???????? 399e94841e00 59 57 7517 }
            // n = 7, score = 100
            //   57                   | push                edi
            //   898694841e00         | mov                 dword ptr [esi + 0x1e8494], eax
            //   e8????????           |                     
            //   399e94841e00         | cmp                 dword ptr [esi + 0x1e8494], ebx
            //   59                   | pop                 ecx
            //   57                   | push                edi
            //   7517                 | jne                 0x19

        $sequence_7 = { 85c0 7508 83c8ff e9???????? 8d85c8fdffff 56 50 }
            // n = 7, score = 100
            //   85c0                 | test                eax, eax
            //   7508                 | jne                 0xa
            //   83c8ff               | or                  eax, 0xffffffff
            //   e9????????           |                     
            //   8d85c8fdffff         | lea                 eax, [ebp - 0x238]
            //   56                   | push                esi
            //   50                   | push                eax

        $sequence_8 = { 53 e8???????? 83c410 e8???????? 53 e8???????? }
            // n = 6, score = 100
            //   53                   | push                ebx
            //   e8????????           |                     
            //   83c410               | add                 esp, 0x10
            //   e8????????           |                     
            //   53                   | push                ebx
            //   e8????????           |                     

        $sequence_9 = { 03c3 0345fc 50 e8???????? 6801280000 8d85d8d7ffff }
            // n = 6, score = 100
            //   03c3                 | add                 eax, ebx
            //   0345fc               | add                 eax, dword ptr [ebp - 4]
            //   50                   | push                eax
            //   e8????????           |                     
            //   6801280000           | push                0x2801
            //   8d85d8d7ffff         | lea                 eax, [ebp - 0x2828]

    condition:
        7 of them and filesize < 8060928
}