rule win_deathransom_auto {

    meta:
        author = "Felix Bilstein - yara-signator at cocacoding dot com"
        date = "2022-04-08"
        version = "1"
        description = "Detects win.deathransom."
        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.deathransom"
        malpedia_rule_date = "20220405"
        malpedia_hash = "ecd38294bd47d5589be5cd5490dc8bb4804afc2a"
        malpedia_version = "20220411"
        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 = { 2345e4 0b75e4 2375dc 0bf0 8975e0 014de0 8b4db0 }
            // n = 7, score = 100
            //   2345e4               | and                 eax, dword ptr [ebp - 0x1c]
            //   0b75e4               | or                  esi, dword ptr [ebp - 0x1c]
            //   2375dc               | and                 esi, dword ptr [ebp - 0x24]
            //   0bf0                 | or                  esi, eax
            //   8975e0               | mov                 dword ptr [ebp - 0x20], esi
            //   014de0               | add                 dword ptr [ebp - 0x20], ecx
            //   8b4db0               | mov                 ecx, dword ptr [ebp - 0x50]

        $sequence_1 = { 0b5dec 2345ec 235df0 0bd8 895de4 014de4 }
            // n = 6, score = 100
            //   0b5dec               | or                  ebx, dword ptr [ebp - 0x14]
            //   2345ec               | and                 eax, dword ptr [ebp - 0x14]
            //   235df0               | and                 ebx, dword ptr [ebp - 0x10]
            //   0bd8                 | or                  ebx, eax
            //   895de4               | mov                 dword ptr [ebp - 0x1c], ebx
            //   014de4               | add                 dword ptr [ebp - 0x1c], ecx

        $sequence_2 = { 50 ff15???????? 8945fc 8d50ff 33c9 03d6 }
            // n = 6, score = 100
            //   50                   | push                eax
            //   ff15????????         |                     
            //   8945fc               | mov                 dword ptr [ebp - 4], eax
            //   8d50ff               | lea                 edx, dword ptr [eax - 1]
            //   33c9                 | xor                 ecx, ecx
            //   03d6                 | add                 edx, esi

        $sequence_3 = { 33d2 f7f6 8bd0 0fb7c3 8bca 0fafc2 0fafce }
            // n = 7, score = 100
            //   33d2                 | xor                 edx, edx
            //   f7f6                 | div                 esi
            //   8bd0                 | mov                 edx, eax
            //   0fb7c3               | movzx               eax, bx
            //   8bca                 | mov                 ecx, edx
            //   0fafc2               | imul                eax, edx
            //   0fafce               | imul                ecx, esi

        $sequence_4 = { 0fb6420f c1e108 0bc8 0fb64211 894d9c }
            // n = 5, score = 100
            //   0fb6420f             | movzx               eax, byte ptr [edx + 0xf]
            //   c1e108               | shl                 ecx, 8
            //   0bc8                 | or                  ecx, eax
            //   0fb64211             | movzx               eax, byte ptr [edx + 0x11]
            //   894d9c               | mov                 dword ptr [ebp - 0x64], ecx

        $sequence_5 = { 7508 893c81 33f6 40 33ff 836dfc01 8d5bff }
            // n = 7, score = 100
            //   7508                 | jne                 0xa
            //   893c81               | mov                 dword ptr [ecx + eax*4], edi
            //   33f6                 | xor                 esi, esi
            //   40                   | inc                 eax
            //   33ff                 | xor                 edi, edi
            //   836dfc01             | sub                 dword ptr [ebp - 4], 1
            //   8d5bff               | lea                 ebx, dword ptr [ebx - 1]

        $sequence_6 = { 8b7d10 8bc1 8945fc 8bf2 83ff01 7516 ff7514 }
            // n = 7, score = 100
            //   8b7d10               | mov                 edi, dword ptr [ebp + 0x10]
            //   8bc1                 | mov                 eax, ecx
            //   8945fc               | mov                 dword ptr [ebp - 4], eax
            //   8bf2                 | mov                 esi, edx
            //   83ff01               | cmp                 edi, 1
            //   7516                 | jne                 0x18
            //   ff7514               | push                dword ptr [ebp + 0x14]

        $sequence_7 = { e8???????? 83c414 8d8d10fdffff 33d2 68???????? 83ec10 e8???????? }
            // n = 7, score = 100
            //   e8????????           |                     
            //   83c414               | add                 esp, 0x14
            //   8d8d10fdffff         | lea                 ecx, dword ptr [ebp - 0x2f0]
            //   33d2                 | xor                 edx, edx
            //   68????????           |                     
            //   83ec10               | sub                 esp, 0x10
            //   e8????????           |                     

        $sequence_8 = { 894304 8b5708 8b470c 2b5308 895308 1b430c 89430c }
            // n = 7, score = 100
            //   894304               | mov                 dword ptr [ebx + 4], eax
            //   8b5708               | mov                 edx, dword ptr [edi + 8]
            //   8b470c               | mov                 eax, dword ptr [edi + 0xc]
            //   2b5308               | sub                 edx, dword ptr [ebx + 8]
            //   895308               | mov                 dword ptr [ebx + 8], edx
            //   1b430c               | sbb                 eax, dword ptr [ebx + 0xc]
            //   89430c               | mov                 dword ptr [ebx + 0xc], eax

        $sequence_9 = { 0f8591000000 ff75f8 6a08 ff15???????? }
            // n = 4, score = 100
            //   0f8591000000         | jne                 0x97
            //   ff75f8               | push                dword ptr [ebp - 8]
            //   6a08                 | push                8
            //   ff15????????         |                     

    condition:
        7 of them and filesize < 133120
}