rule win_blackenergy_auto {

    meta:
        author = "Felix Bilstein - yara-signator at cocacoding dot com"
        date = "2023-03-28"
        version = "1"
        description = "Detects win.blackenergy."
        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.blackenergy"
        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 = { 6a40 ff15???????? 8b4d18 8901 3bc7 750c ff75fc }
            // n = 7, score = 200
            //   6a40                 | push                0x40
            //   ff15????????         |                     
            //   8b4d18               | mov                 ecx, dword ptr [ebp + 0x18]
            //   8901                 | mov                 dword ptr [ecx], eax
            //   3bc7                 | cmp                 eax, edi
            //   750c                 | jne                 0xe
            //   ff75fc               | push                dword ptr [ebp - 4]

        $sequence_1 = { e8???????? 8945e8 8b7df0 be???????? 8b4de8 f3a4 }
            // n = 6, score = 200
            //   e8????????           |                     
            //   8945e8               | mov                 dword ptr [ebp - 0x18], eax
            //   8b7df0               | mov                 edi, dword ptr [ebp - 0x10]
            //   be????????           |                     
            //   8b4de8               | mov                 ecx, dword ptr [ebp - 0x18]
            //   f3a4                 | rep movsb           byte ptr es:[edi], byte ptr [esi]

        $sequence_2 = { 0fb6c9 0fb6c0 2bc1 e9???????? 8b35???????? 8b7de8 ebc5 }
            // n = 7, score = 200
            //   0fb6c9               | movzx               ecx, cl
            //   0fb6c0               | movzx               eax, al
            //   2bc1                 | sub                 eax, ecx
            //   e9????????           |                     
            //   8b35????????         |                     
            //   8b7de8               | mov                 edi, dword ptr [ebp - 0x18]
            //   ebc5                 | jmp                 0xffffffc7

        $sequence_3 = { 50 50 33c9 41 d1e8 75fb 58 }
            // n = 7, score = 200
            //   50                   | push                eax
            //   50                   | push                eax
            //   33c9                 | xor                 ecx, ecx
            //   41                   | inc                 ecx
            //   d1e8                 | shr                 eax, 1
            //   75fb                 | jne                 0xfffffffd
            //   58                   | pop                 eax

        $sequence_4 = { 57 8d442438 50 b8???????? e8???????? }
            // n = 5, score = 200
            //   57                   | push                edi
            //   8d442438             | lea                 eax, [esp + 0x38]
            //   50                   | push                eax
            //   b8????????           |                     
            //   e8????????           |                     

        $sequence_5 = { 33c0 6689442454 53 56 57 8d7c2462 }
            // n = 6, score = 200
            //   33c0                 | xor                 eax, eax
            //   6689442454           | mov                 word ptr [esp + 0x54], ax
            //   53                   | push                ebx
            //   56                   | push                esi
            //   57                   | push                edi
            //   8d7c2462             | lea                 edi, [esp + 0x62]

        $sequence_6 = { 75ae 5e 5f c9 }
            // n = 4, score = 200
            //   75ae                 | jne                 0xffffffb0
            //   5e                   | pop                 esi
            //   5f                   | pop                 edi
            //   c9                   | leave               

        $sequence_7 = { 743a 8b16 8bcf e8???????? ba???????? e8???????? 8b5508 }
            // n = 7, score = 200
            //   743a                 | je                  0x3c
            //   8b16                 | mov                 edx, dword ptr [esi]
            //   8bcf                 | mov                 ecx, edi
            //   e8????????           |                     
            //   ba????????           |                     
            //   e8????????           |                     
            //   8b5508               | mov                 edx, dword ptr [ebp + 8]

        $sequence_8 = { 7502 8bd6 a1???????? 8bc8 85c0 7502 8bce }
            // n = 7, score = 200
            //   7502                 | jne                 4
            //   8bd6                 | mov                 edx, esi
            //   a1????????           |                     
            //   8bc8                 | mov                 ecx, eax
            //   85c0                 | test                eax, eax
            //   7502                 | jne                 4
            //   8bce                 | mov                 ecx, esi

        $sequence_9 = { c745e06e65742e c745e4646c6c00 3bfb 753e 64a130000000 8b400c 8b400c }
            // n = 7, score = 200
            //   c745e06e65742e       | mov                 dword ptr [ebp - 0x20], 0x2e74656e
            //   c745e4646c6c00       | mov                 dword ptr [ebp - 0x1c], 0x6c6c64
            //   3bfb                 | cmp                 edi, ebx
            //   753e                 | jne                 0x40
            //   64a130000000         | mov                 eax, dword ptr fs:[0x30]
            //   8b400c               | mov                 eax, dword ptr [eax + 0xc]
            //   8b400c               | mov                 eax, dword ptr [eax + 0xc]

    condition:
        7 of them and filesize < 98304
}