rule win_blackenergy_auto {

    meta:
        author = "Felix Bilstein - yara-signator at cocacoding dot com"
        date = "2026-09-17"
        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 = "20260916"
        malpedia_hash = "53a643781c18e08f4a50949af60172d837a0b6f6"
        malpedia_version = "20260917"
        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 = { 6a02 895de8 8975e4 e8???????? 8d4de4 51 8d4de8 }
            // n = 7, score = 200
            //   6a02                 | push                2
            //   895de8               | mov                 dword ptr [ebp - 0x18], ebx
            //   8975e4               | mov                 dword ptr [ebp - 0x1c], esi
            //   e8????????           |                     
            //   8d4de4               | lea                 ecx, [ebp - 0x1c]
            //   51                   | push                ecx
            //   8d4de8               | lea                 ecx, [ebp - 0x18]

        $sequence_1 = { 8b7628 3bf3 75e5 ff75f8 ffd7 }
            // n = 5, score = 200
            //   8b7628               | mov                 esi, dword ptr [esi + 0x28]
            //   3bf3                 | cmp                 esi, ebx
            //   75e5                 | jne                 0xffffffe7
            //   ff75f8               | push                dword ptr [ebp - 8]
            //   ffd7                 | call                edi

        $sequence_2 = { b800000000 b99c000000 f3aa 8d855cffffff }
            // n = 4, score = 200
            //   b800000000           | mov                 eax, 0
            //   b99c000000           | mov                 ecx, 0x9c
            //   f3aa                 | rep stosb           byte ptr es:[edi], al
            //   8d855cffffff         | lea                 eax, [ebp - 0xa4]

        $sequence_3 = { 81ec7c0a0000 56 be14050000 56 8d8598faffff 50 ff7508 }
            // n = 7, score = 200
            //   81ec7c0a0000         | sub                 esp, 0xa7c
            //   56                   | push                esi
            //   be14050000           | mov                 esi, 0x514
            //   56                   | push                esi
            //   8d8598faffff         | lea                 eax, [ebp - 0x568]
            //   50                   | push                eax
            //   ff7508               | push                dword ptr [ebp + 8]

        $sequence_4 = { 58 49 d1e1 014df4 }
            // n = 4, score = 200
            //   58                   | pop                 eax
            //   49                   | dec                 ecx
            //   d1e1                 | shl                 ecx, 1
            //   014df4               | add                 dword ptr [ebp - 0xc], ecx

        $sequence_5 = { 8b75d4 8b4de0 f3a4 8bc8 e8???????? 0345f4 }
            // n = 6, score = 200
            //   8b75d4               | mov                 esi, dword ptr [ebp - 0x2c]
            //   8b4de0               | mov                 ecx, dword ptr [ebp - 0x20]
            //   f3a4                 | rep movsb           byte ptr es:[edi], byte ptr [esi]
            //   8bc8                 | mov                 ecx, eax
            //   e8????????           |                     
            //   0345f4               | add                 eax, dword ptr [ebp - 0xc]

        $sequence_6 = { e8???????? 6639bdcaf7ffff 740d 8d85c8f7ffff 50 ff15???????? 8d45f4 }
            // n = 7, score = 200
            //   e8????????           |                     
            //   6639bdcaf7ffff       | cmp                 word ptr [ebp - 0x836], di
            //   740d                 | je                  0xf
            //   8d85c8f7ffff         | lea                 eax, [ebp - 0x838]
            //   50                   | push                eax
            //   ff15????????         |                     
            //   8d45f4               | lea                 eax, [ebp - 0xc]

        $sequence_7 = { 8365f800 53 56 57 ff750c 8bf8 e8???????? }
            // n = 7, score = 200
            //   8365f800             | and                 dword ptr [ebp - 8], 0
            //   53                   | push                ebx
            //   56                   | push                esi
            //   57                   | push                edi
            //   ff750c               | push                dword ptr [ebp + 0xc]
            //   8bf8                 | mov                 edi, eax
            //   e8????????           |                     

        $sequence_8 = { 85f6 7423 0fb74624 8b4e28 d1e8 8d4c41e8 }
            // n = 6, score = 200
            //   85f6                 | test                esi, esi
            //   7423                 | je                  0x25
            //   0fb74624             | movzx               eax, word ptr [esi + 0x24]
            //   8b4e28               | mov                 ecx, dword ptr [esi + 0x28]
            //   d1e8                 | shr                 eax, 1
            //   8d4c41e8             | lea                 ecx, [ecx + eax*2 - 0x18]

        $sequence_9 = { c745ec01000000 8b45ec 5e eb02 33c0 5f 5b }
            // n = 7, score = 200
            //   c745ec01000000       | mov                 dword ptr [ebp - 0x14], 1
            //   8b45ec               | mov                 eax, dword ptr [ebp - 0x14]
            //   5e                   | pop                 esi
            //   eb02                 | jmp                 4
            //   33c0                 | xor                 eax, eax
            //   5f                   | pop                 edi
            //   5b                   | pop                 ebx

    condition:
        7 of them and filesize < 98304
}