rule win_bitsran_auto {

    meta:
        author = "Felix Bilstein - yara-signator at cocacoding dot com"
        date = "2023-07-11"
        version = "1"
        description = "Detects win.bitsran."
        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.bitsran"
        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 = { c3 8bff 56 57 33ff ffb7b0104200 ff15???????? }
            // n = 7, score = 100
            //   c3                   | ret                 
            //   8bff                 | mov                 edi, edi
            //   56                   | push                esi
            //   57                   | push                edi
            //   33ff                 | xor                 edi, edi
            //   ffb7b0104200         | push                dword ptr [edi + 0x4210b0]
            //   ff15????????         |                     

        $sequence_1 = { 7515 5f b8384a0000 5e }
            // n = 4, score = 100
            //   7515                 | jne                 0x17
            //   5f                   | pop                 edi
            //   b8384a0000           | mov                 eax, 0x4a38
            //   5e                   | pop                 esi

        $sequence_2 = { 8b4510 33c9 66894804 89882c020000 8b4d08 }
            // n = 5, score = 100
            //   8b4510               | mov                 eax, dword ptr [ebp + 0x10]
            //   33c9                 | xor                 ecx, ecx
            //   66894804             | mov                 word ptr [eax + 4], cx
            //   89882c020000         | mov                 dword ptr [eax + 0x22c], ecx
            //   8b4d08               | mov                 ecx, dword ptr [ebp + 8]

        $sequence_3 = { d1f8 7517 57 ff15???????? }
            // n = 4, score = 100
            //   d1f8                 | sar                 eax, 1
            //   7517                 | jne                 0x19
            //   57                   | push                edi
            //   ff15????????         |                     

        $sequence_4 = { 53 57 ff15???????? 8985c4fcffff 85c0 0f840c020000 }
            // n = 6, score = 100
            //   53                   | push                ebx
            //   57                   | push                edi
            //   ff15????????         |                     
            //   8985c4fcffff         | mov                 dword ptr [ebp - 0x33c], eax
            //   85c0                 | test                eax, eax
            //   0f840c020000         | je                  0x212

        $sequence_5 = { 742b 8bc1 2bc1 c1f802 8d348500000000 }
            // n = 5, score = 100
            //   742b                 | je                  0x2d
            //   8bc1                 | mov                 eax, ecx
            //   2bc1                 | sub                 eax, ecx
            //   c1f802               | sar                 eax, 2
            //   8d348500000000       | lea                 esi, [eax*4]

        $sequence_6 = { 6685c9 743f 33c0 8945ee 8945f2 8945f6 668945fa }
            // n = 7, score = 100
            //   6685c9               | test                cx, cx
            //   743f                 | je                  0x41
            //   33c0                 | xor                 eax, eax
            //   8945ee               | mov                 dword ptr [ebp - 0x12], eax
            //   8945f2               | mov                 dword ptr [ebp - 0xe], eax
            //   8945f6               | mov                 dword ptr [ebp - 0xa], eax
            //   668945fa             | mov                 word ptr [ebp - 6], ax

        $sequence_7 = { e8???????? 83c40c 83f8ff 7440 50 e8???????? 83c404 }
            // n = 7, score = 100
            //   e8????????           |                     
            //   83c40c               | add                 esp, 0xc
            //   83f8ff               | cmp                 eax, -1
            //   7440                 | je                  0x42
            //   50                   | push                eax
            //   e8????????           |                     
            //   83c404               | add                 esp, 4

        $sequence_8 = { 56 668945ee e8???????? 8b4dfc 33cd }
            // n = 5, score = 100
            //   56                   | push                esi
            //   668945ee             | mov                 word ptr [ebp - 0x12], ax
            //   e8????????           |                     
            //   8b4dfc               | mov                 ecx, dword ptr [ebp - 4]
            //   33cd                 | xor                 ecx, ebp

        $sequence_9 = { 7407 838b0c02000002 84d2 7407 838b0c02000001 80bdecfcffff00 }
            // n = 6, score = 100
            //   7407                 | je                  9
            //   838b0c02000002       | or                  dword ptr [ebx + 0x20c], 2
            //   84d2                 | test                dl, dl
            //   7407                 | je                  9
            //   838b0c02000001       | or                  dword ptr [ebx + 0x20c], 1
            //   80bdecfcffff00       | cmp                 byte ptr [ebp - 0x314], 0

    condition:
        7 of them and filesize < 344064
}