rule win_polyglot_ransom_auto {

    meta:
        author = "Felix Bilstein - yara-signator at cocacoding dot com"
        date = "2022-05-16"
        version = "1"
        description = "Detects win.polyglot_ransom."
        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.polyglot_ransom"
        malpedia_rule_date = "20220513"
        malpedia_hash = "7f4b2229e6ae614d86d74917f6d5b41890e62a26"
        malpedia_version = "20220516"
        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 = { 50 8d85c4efffff 50 e8???????? 53 8d85fcefffff 50 }
            // n = 7, score = 100
            //   50                   | push                eax
            //   8d85c4efffff         | lea                 eax, [ebp - 0x103c]
            //   50                   | push                eax
            //   e8????????           |                     
            //   53                   | push                ebx
            //   8d85fcefffff         | lea                 eax, [ebp - 0x1004]
            //   50                   | push                eax

        $sequence_1 = { 50 898534d9ffff e8???????? 83c440 ffb534d9ffff 8bd8 56 }
            // n = 7, score = 100
            //   50                   | push                eax
            //   898534d9ffff         | mov                 dword ptr [ebp - 0x26cc], eax
            //   e8????????           |                     
            //   83c440               | add                 esp, 0x40
            //   ffb534d9ffff         | push                dword ptr [ebp - 0x26cc]
            //   8bd8                 | mov                 ebx, eax
            //   56                   | push                esi

        $sequence_2 = { 59 8d7e50 59 8907 895e54 33db 395e54 }
            // n = 7, score = 100
            //   59                   | pop                 ecx
            //   8d7e50               | lea                 edi, [esi + 0x50]
            //   59                   | pop                 ecx
            //   8907                 | mov                 dword ptr [edi], eax
            //   895e54               | mov                 dword ptr [esi + 0x54], ebx
            //   33db                 | xor                 ebx, ebx
            //   395e54               | cmp                 dword ptr [esi + 0x54], ebx

        $sequence_3 = { 69667261646f20 6465207072 7565 62612e 3c2f 68313e0d0a 3c73 }
            // n = 7, score = 100
            //   69667261646f20       | imul                esp, dword ptr [esi + 0x72], 0x206f6461
            //   6465207072           | and                 byte ptr gs:[eax + 0x72], dh
            //   7565                 | jne                 0x67
            //   62612e               | bound               esp, qword ptr [ecx + 0x2e]
            //   3c2f                 | cmp                 al, 0x2f
            //   68313e0d0a           | push                0xa0d3e31
            //   3c73                 | cmp                 al, 0x73

        $sequence_4 = { 8bc3 56 50 e8???????? 85c0 59 59 }
            // n = 7, score = 100
            //   8bc3                 | mov                 eax, ebx
            //   56                   | push                esi
            //   50                   | push                eax
            //   e8????????           |                     
            //   85c0                 | test                eax, eax
            //   59                   | pop                 ecx
            //   59                   | pop                 ecx

        $sequence_5 = { 656d 657265 2027 52 6970726f766127 3c70 2f }
            // n = 7, score = 100
            //   656d                 | insd                dword ptr es:[edi], dx
            //   657265               | jb                  0x68
            //   2027                 | and                 byte ptr [edi], ah
            //   52                   | push                edx
            //   6970726f766127       | imul                esi, dword ptr [eax + 0x72], 0x2761766f
            //   3c70                 | cmp                 al, 0x70
            //   2f                   | das                 

        $sequence_6 = { e8???????? 59 e8???????? 50 8d8dbcefffff e8???????? c645fc02 }
            // n = 7, score = 100
            //   e8????????           |                     
            //   59                   | pop                 ecx
            //   e8????????           |                     
            //   50                   | push                eax
            //   8d8dbcefffff         | lea                 ecx, [ebp - 0x1044]
            //   e8????????           |                     
            //   c645fc02             | mov                 byte ptr [ebp - 4], 2

        $sequence_7 = { e8???????? 8b06 8bce 897e44 ff5010 8b4508 834dccff }
            // n = 7, score = 100
            //   e8????????           |                     
            //   8b06                 | mov                 eax, dword ptr [esi]
            //   8bce                 | mov                 ecx, esi
            //   897e44               | mov                 dword ptr [esi + 0x44], edi
            //   ff5010               | call                dword ptr [eax + 0x10]
            //   8b4508               | mov                 eax, dword ptr [ebp + 8]
            //   834dccff             | or                  dword ptr [ebp - 0x34], 0xffffffff

        $sequence_8 = { 837df800 7616 8b8608010000 ff75f8 ff7004 ff30 e8???????? }
            // n = 7, score = 100
            //   837df800             | cmp                 dword ptr [ebp - 8], 0
            //   7616                 | jbe                 0x18
            //   8b8608010000         | mov                 eax, dword ptr [esi + 0x108]
            //   ff75f8               | push                dword ptr [ebp - 8]
            //   ff7004               | push                dword ptr [eax + 4]
            //   ff30                 | push                dword ptr [eax]
            //   e8????????           |                     

        $sequence_9 = { 894624 740c 50 e8???????? }
            // n = 4, score = 100
            //   894624               | mov                 dword ptr [esi + 0x24], eax
            //   740c                 | je                  0xe
            //   50                   | push                eax
            //   e8????????           |                     

    condition:
        7 of them and filesize < 1392640
}