rule win_blackmatter_auto {

    meta:
        author = "Felix Bilstein - yara-signator at cocacoding dot com"
        date = "2026-05-04"
        version = "1"
        description = "Detects win.blackmatter."
        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.blackmatter"
        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 = { 8bd8 8d045d02000000 50 57 8d0477 50 ff15???????? }
            // n = 7, score = 400
            //   8bd8                 | mov                 ebx, eax
            //   8d045d02000000       | lea                 eax, [ebx*2 + 2]
            //   50                   | push                eax
            //   57                   | push                edi
            //   8d0477               | lea                 eax, [edi + esi*2]
            //   50                   | push                eax
            //   ff15????????         |                     

        $sequence_1 = { 837dfc00 7402 eb0b 8b09 }
            // n = 4, score = 400
            //   837dfc00             | cmp                 dword ptr [ebp - 4], 0
            //   7402                 | je                  4
            //   eb0b                 | jmp                 0xd
            //   8b09                 | mov                 ecx, dword ptr [ecx]

        $sequence_2 = { ff15???????? 85c0 754f c745f801000000 c745f480000000 8d45f4 }
            // n = 6, score = 400
            //   ff15????????         |                     
            //   85c0                 | test                eax, eax
            //   754f                 | jne                 0x51
            //   c745f801000000       | mov                 dword ptr [ebp - 8], 1
            //   c745f480000000       | mov                 dword ptr [ebp - 0xc], 0x80
            //   8d45f4               | lea                 eax, [ebp - 0xc]

        $sequence_3 = { 75df 8bc2 5e 5a 5d }
            // n = 5, score = 400
            //   75df                 | jne                 0xffffffe1
            //   8bc2                 | mov                 eax, edx
            //   5e                   | pop                 esi
            //   5a                   | pop                 edx
            //   5d                   | pop                 ebp

        $sequence_4 = { c745fc00000000 8d8532ffffff 50 e8???????? }
            // n = 4, score = 400
            //   c745fc00000000       | mov                 dword ptr [ebp - 4], 0
            //   8d8532ffffff         | lea                 eax, [ebp - 0xce]
            //   50                   | push                eax
            //   e8????????           |                     

        $sequence_5 = { eb18 ff75f0 ff15???????? ff75f0 e8???????? c745f000000000 }
            // n = 6, score = 400
            //   eb18                 | jmp                 0x1a
            //   ff75f0               | push                dword ptr [ebp - 0x10]
            //   ff15????????         |                     
            //   ff75f0               | push                dword ptr [ebp - 0x10]
            //   e8????????           |                     
            //   c745f000000000       | mov                 dword ptr [ebp - 0x10], 0

        $sequence_6 = { 03f3 03fb ad 03c3 ff75f4 }
            // n = 5, score = 400
            //   03f3                 | add                 esi, ebx
            //   03fb                 | add                 edi, ebx
            //   ad                   | lodsd               eax, dword ptr [esi]
            //   03c3                 | add                 eax, ebx
            //   ff75f4               | push                dword ptr [ebp - 0xc]

        $sequence_7 = { 7409 83f802 0f857c010000 e8???????? }
            // n = 4, score = 400
            //   7409                 | je                  0xb
            //   83f802               | cmp                 eax, 2
            //   0f857c010000         | jne                 0x182
            //   e8????????           |                     

        $sequence_8 = { 75bf ff75f8 ff15???????? 837df400 7408 ff75f4 }
            // n = 6, score = 400
            //   75bf                 | jne                 0xffffffc1
            //   ff75f8               | push                dword ptr [ebp - 8]
            //   ff15????????         |                     
            //   837df400             | cmp                 dword ptr [ebp - 0xc], 0
            //   7408                 | je                  0xa
            //   ff75f4               | push                dword ptr [ebp - 0xc]

        $sequence_9 = { 83c40c 56 e8???????? 8b75e8 64a130000000 8b80d4010000 }
            // n = 6, score = 400
            //   83c40c               | add                 esp, 0xc
            //   56                   | push                esi
            //   e8????????           |                     
            //   8b75e8               | mov                 esi, dword ptr [ebp - 0x18]
            //   64a130000000         | mov                 eax, dword ptr fs:[0x30]
            //   8b80d4010000         | mov                 eax, dword ptr [eax + 0x1d4]

    condition:
        7 of them and filesize < 194560
}