rule win_bbsrat_auto {

    meta:
        author = "Felix Bilstein - yara-signator at cocacoding dot com"
        date = "2022-08-05"
        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 = "20220805"
        malpedia_hash = "6ec06c64bcfdbeda64eff021c766b4ce34542b71"
        malpedia_version = "20220808"
        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 = { 0f84f4000000 03f8 83ff1c 7cc0 8b4504 2537010000 3d37010000 }
            // n = 7, score = 100
            //   0f84f4000000         | je                  0xfa
            //   03f8                 | add                 edi, eax
            //   83ff1c               | cmp                 edi, 0x1c
            //   7cc0                 | jl                  0xffffffc2
            //   8b4504               | mov                 eax, dword ptr [ebp + 4]
            //   2537010000           | and                 eax, 0x137
            //   3d37010000           | cmp                 eax, 0x137

        $sequence_1 = { 53 33c9 6a01 66898c2488000000 8b0d???????? 53 898c24a4000000 }
            // n = 7, score = 100
            //   53                   | push                ebx
            //   33c9                 | xor                 ecx, ecx
            //   6a01                 | push                1
            //   66898c2488000000     | mov                 word ptr [esp + 0x88], cx
            //   8b0d????????         |                     
            //   53                   | push                ebx
            //   898c24a4000000       | mov                 dword ptr [esp + 0xa4], ecx

        $sequence_2 = { ff15???????? 8b74240c 89442408 e9???????? 8d442410 50 6808000200 }
            // n = 7, score = 100
            //   ff15????????         |                     
            //   8b74240c             | mov                 esi, dword ptr [esp + 0xc]
            //   89442408             | mov                 dword ptr [esp + 8], eax
            //   e9????????           |                     
            //   8d442410             | lea                 eax, [esp + 0x10]
            //   50                   | push                eax
            //   6808000200           | push                0x20008

        $sequence_3 = { c7020d000000 8b461c c7461808b00210 c7400400000000 5f 5e 5d }
            // n = 7, score = 100
            //   c7020d000000         | mov                 dword ptr [edx], 0xd
            //   8b461c               | mov                 eax, dword ptr [esi + 0x1c]
            //   c7461808b00210       | mov                 dword ptr [esi + 0x18], 0x1002b008
            //   c7400400000000       | mov                 dword ptr [eax + 4], 0
            //   5f                   | pop                 edi
            //   5e                   | pop                 esi
            //   5d                   | pop                 ebp

        $sequence_4 = { 0fb716 0fb7c2 8d48bf 83f919 7703 83c020 0fb70f }
            // n = 7, score = 100
            //   0fb716               | movzx               edx, word ptr [esi]
            //   0fb7c2               | movzx               eax, dx
            //   8d48bf               | lea                 ecx, [eax - 0x41]
            //   83f919               | cmp                 ecx, 0x19
            //   7703                 | ja                  5
            //   83c020               | add                 eax, 0x20
            //   0fb70f               | movzx               ecx, word ptr [edi]

        $sequence_5 = { 807b1000 75ec 5e 33c0 5b 8be5 }
            // n = 6, score = 100
            //   807b1000             | cmp                 byte ptr [ebx + 0x10], 0
            //   75ec                 | jne                 0xffffffee
            //   5e                   | pop                 esi
            //   33c0                 | xor                 eax, eax
            //   5b                   | pop                 ebx
            //   8be5                 | mov                 esp, ebp

        $sequence_6 = { 83c404 57 e8???????? 8b4c2420 83c404 51 }
            // n = 6, score = 100
            //   83c404               | add                 esp, 4
            //   57                   | push                edi
            //   e8????????           |                     
            //   8b4c2420             | mov                 ecx, dword ptr [esp + 0x20]
            //   83c404               | add                 esp, 4
            //   51                   | push                ecx

        $sequence_7 = { f74704???????? 746e 8b4714 50 e8???????? 83c404 }
            // n = 6, score = 100
            //   f74704????????       |                     
            //   746e                 | je                  0x70
            //   8b4714               | mov                 eax, dword ptr [edi + 0x14]
            //   50                   | push                eax
            //   e8????????           |                     
            //   83c404               | add                 esp, 4

        $sequence_8 = { eb4b 8b442404 8d4c240c 51 6a04 8d542410 52 }
            // n = 7, score = 100
            //   eb4b                 | jmp                 0x4d
            //   8b442404             | mov                 eax, dword ptr [esp + 4]
            //   8d4c240c             | lea                 ecx, [esp + 0xc]
            //   51                   | push                ecx
            //   6a04                 | push                4
            //   8d542410             | lea                 edx, [esp + 0x10]
            //   52                   | push                edx

        $sequence_9 = { 8d9424d2020000 52 66898c24d4020000 e8???????? 33c0 68fe010000 50 }
            // n = 7, score = 100
            //   8d9424d2020000       | lea                 edx, [esp + 0x2d2]
            //   52                   | push                edx
            //   66898c24d4020000     | mov                 word ptr [esp + 0x2d4], cx
            //   e8????????           |                     
            //   33c0                 | xor                 eax, eax
            //   68fe010000           | push                0x1fe
            //   50                   | push                eax

    condition:
        7 of them and filesize < 434176
}