rule win_bbsrat_auto {

    meta:
        author = "Felix Bilstein - yara-signator at cocacoding dot com"
        date = "2023-03-28"
        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 = "20230328"
        malpedia_hash = "9d2d75cef573c1c2d861f5197df8f563b05a305d"
        malpedia_version = "20230407"
        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 = { 740e bf00800c00 8bf0 e8???????? eb02 33c0 55 }
            // n = 7, score = 100
            //   740e                 | je                  0x10
            //   bf00800c00           | mov                 edi, 0xc8000
            //   8bf0                 | mov                 esi, eax
            //   e8????????           |                     
            //   eb02                 | jmp                 4
            //   33c0                 | xor                 eax, eax
            //   55                   | push                ebp

        $sequence_1 = { 56 33f6 68fc0f0000 8d442458 56 50 }
            // n = 6, score = 100
            //   56                   | push                esi
            //   33f6                 | xor                 esi, esi
            //   68fc0f0000           | push                0xffc
            //   8d442458             | lea                 eax, [esp + 0x58]
            //   56                   | push                esi
            //   50                   | push                eax

        $sequence_2 = { 0f87dd090000 ff248503bc0110 33c0 838df4fbffffff 8985a4fbffff 8985b0fbffff 8985d4fbffff }
            // n = 7, score = 100
            //   0f87dd090000         | ja                  0x9e3
            //   ff248503bc0110       | jmp                 dword ptr [eax*4 + 0x1001bc03]
            //   33c0                 | xor                 eax, eax
            //   838df4fbffffff       | or                  dword ptr [ebp - 0x40c], 0xffffffff
            //   8985a4fbffff         | mov                 dword ptr [ebp - 0x45c], eax
            //   8985b0fbffff         | mov                 dword ptr [ebp - 0x450], eax
            //   8985d4fbffff         | mov                 dword ptr [ebp - 0x42c], eax

        $sequence_3 = { 52 6a05 53 c744243830750000 e8???????? 6a04 }
            // n = 6, score = 100
            //   52                   | push                edx
            //   6a05                 | push                5
            //   53                   | push                ebx
            //   c744243830750000     | mov                 dword ptr [esp + 0x38], 0x7530
            //   e8????????           |                     
            //   6a04                 | push                4

        $sequence_4 = { 50 6a08 ff15???????? 50 ff15???????? 8b542414 8d4c2414 }
            // n = 7, score = 100
            //   50                   | push                eax
            //   6a08                 | push                8
            //   ff15????????         |                     
            //   50                   | push                eax
            //   ff15????????         |                     
            //   8b542414             | mov                 edx, dword ptr [esp + 0x14]
            //   8d4c2414             | lea                 ecx, [esp + 0x14]

        $sequence_5 = { 83c420 6a3a 56 6868001100 55 }
            // n = 5, score = 100
            //   83c420               | add                 esp, 0x20
            //   6a3a                 | push                0x3a
            //   56                   | push                esi
            //   6868001100           | push                0x110068
            //   55                   | push                ebp

        $sequence_6 = { 8bc7 e8???????? 85db 751a e8???????? 33c0 3b7810 }
            // n = 7, score = 100
            //   8bc7                 | mov                 eax, edi
            //   e8????????           |                     
            //   85db                 | test                ebx, ebx
            //   751a                 | jne                 0x1c
            //   e8????????           |                     
            //   33c0                 | xor                 eax, eax
            //   3b7810               | cmp                 edi, dword ptr [eax + 0x10]

        $sequence_7 = { a1???????? 33c4 8984240c020000 33c0 6806020000 50 8d4c240a }
            // n = 7, score = 100
            //   a1????????           |                     
            //   33c4                 | xor                 eax, esp
            //   8984240c020000       | mov                 dword ptr [esp + 0x20c], eax
            //   33c0                 | xor                 eax, eax
            //   6806020000           | push                0x206
            //   50                   | push                eax
            //   8d4c240a             | lea                 ecx, [esp + 0xa]

        $sequence_8 = { 83e30f 2bc3 8b0c9df8c30210 23ca 034e04 894c242c 8bcb }
            // n = 7, score = 100
            //   83e30f               | and                 ebx, 0xf
            //   2bc3                 | sub                 eax, ebx
            //   8b0c9df8c30210       | mov                 ecx, dword ptr [ebx*4 + 0x1002c3f8]
            //   23ca                 | and                 ecx, edx
            //   034e04               | add                 ecx, dword ptr [esi + 4]
            //   894c242c             | mov                 dword ptr [esp + 0x2c], ecx
            //   8bcb                 | mov                 ecx, ebx

        $sequence_9 = { 8d542428 52 6a00 6a00 6a00 6a01 6a00 }
            // n = 7, score = 100
            //   8d542428             | lea                 edx, [esp + 0x28]
            //   52                   | push                edx
            //   6a00                 | push                0
            //   6a00                 | push                0
            //   6a00                 | push                0
            //   6a01                 | push                1
            //   6a00                 | push                0

    condition:
        7 of them and filesize < 434176
}