rule win_blackcoffee_auto {

    meta:
        author = "Felix Bilstein - yara-signator at cocacoding dot com"
        date = "2026-05-04"
        version = "1"
        description = "Detects win.blackcoffee."
        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.blackcoffee"
        malpedia_rule_date = "20260422"
        malpedia_hash = "a182e35da64e6d71cb55f125c4d4225196523f14"
        malpedia_version = "20260504"
        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 = { 89461c 8b45f8 894618 8b461c 83c00c 894610 }
            // n = 6, score = 200
            //   89461c               | mov                 dword ptr [esi + 0x1c], eax
            //   8b45f8               | mov                 eax, dword ptr [ebp - 8]
            //   894618               | mov                 dword ptr [esi + 0x18], eax
            //   8b461c               | mov                 eax, dword ptr [esi + 0x1c]
            //   83c00c               | add                 eax, 0xc
            //   894610               | mov                 dword ptr [esi + 0x10], eax

        $sequence_1 = { e8???????? 8bf0 8d8500fcffff 83c604 33d2 6a08 8bca }
            // n = 7, score = 200
            //   e8????????           |                     
            //   8bf0                 | mov                 esi, eax
            //   8d8500fcffff         | lea                 eax, [ebp - 0x400]
            //   83c604               | add                 esi, 4
            //   33d2                 | xor                 edx, edx
            //   6a08                 | push                8
            //   8bca                 | mov                 ecx, edx

        $sequence_2 = { 59 ff15???????? 0faf4608 ff4508 83c704 837d081e }
            // n = 6, score = 200
            //   59                   | pop                 ecx
            //   ff15????????         |                     
            //   0faf4608             | imul                eax, dword ptr [esi + 8]
            //   ff4508               | inc                 dword ptr [ebp + 8]
            //   83c704               | add                 edi, 4
            //   837d081e             | cmp                 dword ptr [ebp + 8], 0x1e

        $sequence_3 = { ff742414 e8???????? 8bf0 85f6 7411 6888130000 ff15???????? }
            // n = 7, score = 200
            //   ff742414             | push                dword ptr [esp + 0x14]
            //   e8????????           |                     
            //   8bf0                 | mov                 esi, eax
            //   85f6                 | test                esi, esi
            //   7411                 | je                  0x13
            //   6888130000           | push                0x1388
            //   ff15????????         |                     

        $sequence_4 = { 8365fc00 66ab aa 80a508f0ffff00 }
            // n = 4, score = 200
            //   8365fc00             | and                 dword ptr [ebp - 4], 0
            //   66ab                 | stosw               word ptr es:[edi], ax
            //   aa                   | stosb               byte ptr es:[edi], al
            //   80a508f0ffff00       | and                 byte ptr [ebp - 0xff8], 0

        $sequence_5 = { 7620 0fb6543904 8bd8 81e3ff000000 33d3 c1e808 }
            // n = 6, score = 200
            //   7620                 | jbe                 0x22
            //   0fb6543904           | movzx               edx, byte ptr [ecx + edi + 4]
            //   8bd8                 | mov                 ebx, eax
            //   81e3ff000000         | and                 ebx, 0xff
            //   33d3                 | xor                 edx, ebx
            //   c1e808               | shr                 eax, 8

        $sequence_6 = { 6804010000 50 8d4708 50 ffd3 83c418 }
            // n = 6, score = 200
            //   6804010000           | push                0x104
            //   50                   | push                eax
            //   8d4708               | lea                 eax, [edi + 8]
            //   50                   | push                eax
            //   ffd3                 | call                ebx
            //   83c418               | add                 esp, 0x18

        $sequence_7 = { e8???????? 8806 8d45b0 50 }
            // n = 4, score = 200
            //   e8????????           |                     
            //   8806                 | mov                 byte ptr [esi], al
            //   8d45b0               | lea                 eax, [ebp - 0x50]
            //   50                   | push                eax

        $sequence_8 = { 83c00c 0107 8b37 03f3 e8???????? 6854414449 }
            // n = 6, score = 200
            //   83c00c               | add                 eax, 0xc
            //   0107                 | add                 dword ptr [edi], eax
            //   8b37                 | mov                 esi, dword ptr [edi]
            //   03f3                 | add                 esi, ebx
            //   e8????????           |                     
            //   6854414449           | push                0x49444154

        $sequence_9 = { 750b ff15???????? 89460c eb28 57 57 }
            // n = 6, score = 200
            //   750b                 | jne                 0xd
            //   ff15????????         |                     
            //   89460c               | mov                 dword ptr [esi + 0xc], eax
            //   eb28                 | jmp                 0x2a
            //   57                   | push                edi
            //   57                   | push                edi

    condition:
        7 of them and filesize < 118784
}