rule win_bbsrat_auto {

    meta:
        author = "Felix Bilstein - yara-signator at cocacoding dot com"
        date = "2021-06-10"
        version = "1"
        description = "Detects win.bbsrat."
        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.bbsrat"
        malpedia_rule_date = "20210604"
        malpedia_hash = "be09d5d71e77373c0f538068be31a2ad4c69cfbd"
        malpedia_version = "20210616"
        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 = { 8b542414 895004 83461c08 8d8690000000 50 e8???????? 8b4e18 }
            // n = 7, score = 100
            //   8b542414             | mov                 edx, dword ptr [esp + 0x14]
            //   895004               | mov                 dword ptr [eax + 4], edx
            //   83461c08             | add                 dword ptr [esi + 0x1c], 8
            //   8d8690000000         | lea                 eax, dword ptr [esi + 0x90]
            //   50                   | push                eax
            //   e8????????           |                     
            //   8b4e18               | mov                 ecx, dword ptr [esi + 0x18]

        $sequence_1 = { 3bc3 7460 8d742414 e8???????? be01000000 85c0 7504 }
            // n = 7, score = 100
            //   3bc3                 | cmp                 eax, ebx
            //   7460                 | je                  0x62
            //   8d742414             | lea                 esi, dword ptr [esp + 0x14]
            //   e8????????           |                     
            //   be01000000           | mov                 esi, 1
            //   85c0                 | test                eax, eax
            //   7504                 | jne                 6

        $sequence_2 = { 7413 85ff 740f 57 e8???????? 57 e8???????? }
            // n = 7, score = 100
            //   7413                 | je                  0x15
            //   85ff                 | test                edi, edi
            //   740f                 | je                  0x11
            //   57                   | push                edi
            //   e8????????           |                     
            //   57                   | push                edi
            //   e8????????           |                     

        $sequence_3 = { 81ec14020000 a1???????? 33c4 89842410020000 57 33c0 6806020000 }
            // n = 7, score = 100
            //   81ec14020000         | sub                 esp, 0x214
            //   a1????????           |                     
            //   33c4                 | xor                 eax, esp
            //   89842410020000       | mov                 dword ptr [esp + 0x210], eax
            //   57                   | push                edi
            //   33c0                 | xor                 eax, eax
            //   6806020000           | push                0x206

        $sequence_4 = { 8b07 e9???????? 8b3f eb83 8b54240c 52 ff15???????? }
            // n = 7, score = 100
            //   8b07                 | mov                 eax, dword ptr [edi]
            //   e9????????           |                     
            //   8b3f                 | mov                 edi, dword ptr [edi]
            //   eb83                 | jmp                 0xffffff85
            //   8b54240c             | mov                 edx, dword ptr [esp + 0xc]
            //   52                   | push                edx
            //   ff15????????         |                     

        $sequence_5 = { 3b08 7417 3b4804 7415 3b4808 7415 83c604 }
            // n = 7, score = 100
            //   3b08                 | cmp                 ecx, dword ptr [eax]
            //   7417                 | je                  0x19
            //   3b4804               | cmp                 ecx, dword ptr [eax + 4]
            //   7415                 | je                  0x17
            //   3b4808               | cmp                 ecx, dword ptr [eax + 8]
            //   7415                 | je                  0x17
            //   83c604               | add                 esi, 4

        $sequence_6 = { b8???????? a3???????? c705????????b9130210 c705????????6d130210 c705????????a6130210 c705????????0f130210 }
            // n = 6, score = 100
            //   b8????????           |                     
            //   a3????????           |                     
            //   c705????????b9130210     |     
            //   c705????????6d130210     |     
            //   c705????????a6130210     |     
            //   c705????????0f130210     |     

        $sequence_7 = { c20c00 8b4510 50 e8???????? 5e 8be5 5d }
            // n = 7, score = 100
            //   c20c00               | ret                 0xc
            //   8b4510               | mov                 eax, dword ptr [ebp + 0x10]
            //   50                   | push                eax
            //   e8????????           |                     
            //   5e                   | pop                 esi
            //   8be5                 | mov                 esp, ebp
            //   5d                   | pop                 ebp

        $sequence_8 = { c744242463001100 ff15???????? 89442418 8b442438 8b4804 51 }
            // n = 6, score = 100
            //   c744242463001100     | mov                 dword ptr [esp + 0x24], 0x110063
            //   ff15????????         |                     
            //   89442418             | mov                 dword ptr [esp + 0x18], eax
            //   8b442438             | mov                 eax, dword ptr [esp + 0x38]
            //   8b4804               | mov                 ecx, dword ptr [eax + 4]
            //   51                   | push                ecx

        $sequence_9 = { 8bec c7451000100000 833d????????00 7516 68???????? a1???????? 50 }
            // n = 7, score = 100
            //   8bec                 | mov                 ebp, esp
            //   c7451000100000       | mov                 dword ptr [ebp + 0x10], 0x1000
            //   833d????????00       |                     
            //   7516                 | jne                 0x18
            //   68????????           |                     
            //   a1????????           |                     
            //   50                   | push                eax

    condition:
        7 of them and filesize < 434176
}