rule win_rustock_auto {

    meta:
        author = "Felix Bilstein - yara-signator at cocacoding dot com"
        date = "2023-07-11"
        version = "1"
        description = "Detects win.rustock."
        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.rustock"
        malpedia_rule_date = "20230705"
        malpedia_hash = "42d0574f4405bd7d2b154d321d345acb18834a41"
        malpedia_version = "20230715"
        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 = { 21d0 83e100 85c9 7506 68db030100 c3 }
            // n = 6, score = 100
            //   21d0                 | and                 eax, edx
            //   83e100               | and                 ecx, 0
            //   85c9                 | test                ecx, ecx
            //   7506                 | jne                 8
            //   68db030100           | push                0x103db
            //   c3                   | ret                 

        $sequence_1 = { 85f6 7467 c745dc01000000 53 56 ff7510 ff750c }
            // n = 7, score = 100
            //   85f6                 | test                esi, esi
            //   7467                 | je                  0x69
            //   c745dc01000000       | mov                 dword ptr [ebp - 0x24], 1
            //   53                   | push                ebx
            //   56                   | push                esi
            //   ff7510               | push                dword ptr [ebp + 0x10]
            //   ff750c               | push                dword ptr [ebp + 0xc]

        $sequence_2 = { e8???????? 85c0 7420 8d85fcfeffff 50 56 }
            // n = 6, score = 100
            //   e8????????           |                     
            //   85c0                 | test                eax, eax
            //   7420                 | je                  0x22
            //   8d85fcfeffff         | lea                 eax, [ebp - 0x104]
            //   50                   | push                eax
            //   56                   | push                esi

        $sequence_3 = { ff15???????? cc a1???????? 85c0 7402 ffd0 56 }
            // n = 7, score = 100
            //   ff15????????         |                     
            //   cc                   | int3                
            //   a1????????           |                     
            //   85c0                 | test                eax, eax
            //   7402                 | je                  4
            //   ffd0                 | call                eax
            //   56                   | push                esi

        $sequence_4 = { 7404 802700 47 ff06 8b5d0c }
            // n = 5, score = 100
            //   7404                 | je                  6
            //   802700               | and                 byte ptr [edi], 0
            //   47                   | inc                 edi
            //   ff06                 | inc                 dword ptr [esi]
            //   8b5d0c               | mov                 ebx, dword ptr [ebp + 0xc]

        $sequence_5 = { 8d85fcfeffff 50 ff7508 ff15???????? 85c0 6a04 6a00 }
            // n = 7, score = 100
            //   8d85fcfeffff         | lea                 eax, [ebp - 0x104]
            //   50                   | push                eax
            //   ff7508               | push                dword ptr [ebp + 8]
            //   ff15????????         |                     
            //   85c0                 | test                eax, eax
            //   6a04                 | push                4
            //   6a00                 | push                0

        $sequence_6 = { 895dbc 8bcf 33c0 8bfb 8bd1 c1e902 }
            // n = 6, score = 100
            //   895dbc               | mov                 dword ptr [ebp - 0x44], ebx
            //   8bcf                 | mov                 ecx, edi
            //   33c0                 | xor                 eax, eax
            //   8bfb                 | mov                 edi, ebx
            //   8bd1                 | mov                 edx, ecx
            //   c1e902               | shr                 ecx, 2

        $sequence_7 = { 8bf8 ff550c 68c5030000 8bd8 ff550c }
            // n = 5, score = 100
            //   8bf8                 | mov                 edi, eax
            //   ff550c               | call                dword ptr [ebp + 0xc]
            //   68c5030000           | push                0x3c5
            //   8bd8                 | mov                 ebx, eax
            //   ff550c               | call                dword ptr [ebp + 0xc]

        $sequence_8 = { 53 ff15???????? 8d65ac 5f 5e 5b }
            // n = 6, score = 100
            //   53                   | push                ebx
            //   ff15????????         |                     
            //   8d65ac               | lea                 esp, [ebp - 0x54]
            //   5f                   | pop                 edi
            //   5e                   | pop                 esi
            //   5b                   | pop                 ebx

        $sequence_9 = { 8975c0 85f6 0f848b000000 8365fc00 83c003 83e0fc e8???????? }
            // n = 7, score = 100
            //   8975c0               | mov                 dword ptr [ebp - 0x40], esi
            //   85f6                 | test                esi, esi
            //   0f848b000000         | je                  0x91
            //   8365fc00             | and                 dword ptr [ebp - 4], 0
            //   83c003               | add                 eax, 3
            //   83e0fc               | and                 eax, 0xfffffffc
            //   e8????????           |                     

    condition:
        7 of them and filesize < 565248
}