rule win_katz_stealer_auto {

    meta:
        author = "Felix Bilstein - yara-signator at cocacoding dot com"
        date = "2026-09-17"
        version = "1"
        description = "Detects win.katz_stealer."
        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.katz_stealer"
        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 = { 41ffd4 85c0 0f8e8f010000 4898 4889e9 488d157ec20000 c68404101a000000 }
            // n = 7, score = 100
            //   41ffd4               | mov                 ecx, dword ptr [ebp + 0x48]
            //   85c0                 | dec                 eax
            //   0f8e8f010000         | mov                 ecx, dword ptr [ebp + 0x50]
            //   4898                 | dec                 eax
            //   4889e9               | mov                 edx, dword ptr [ebx + 0x20]
            //   488d157ec20000       | inc                 esp
            //   c68404101a000000     | mov                 eax, dword ptr [ebx + 0x10]

        $sequence_1 = { 0f85f1feffff 4c89f1 ff15???????? e9???????? 4c89742420 4d89e1 4c8d0508750000 }
            // n = 7, score = 100
            //   0f85f1feffff         | dec                 eax
            //   4c89f1               | xchg                eax, edi
            //   ff15????????         |                     
            //   e9????????           |                     
            //   4c89742420           | dec                 eax
            //   4d89e1               | mov                 ecx, ebp
            //   4c8d0508750000       | dec                 eax

        $sequence_2 = { 8b9c2488000000 4889d7 4c89c6 4d89cb 81fbff1f0000 7751 }
            // n = 6, score = 100
            //   8b9c2488000000       | xor                 ebp, ebp
            //   4889d7               | dec                 eax
            //   4c89c6               | mov                 dword ptr [esp + 0x20], eax
            //   4d89cb               | inc                 ebp
            //   81fbff1f0000         | xor                 eax, eax
            //   7751                 | dec                 eax

        $sequence_3 = { 4d85db 0f856e020000 4181f97a000780 7575 4883bc24a000000000 7410 488b442450 }
            // n = 7, score = 100
            //   4d85db               | dec                 eax
            //   0f856e020000         | mov                 ecx, ebx
            //   4181f97a000780       | test                eax, eax
            //   7575                 | test                eax, eax
            //   4883bc24a000000000     | je    0x564
            //   7410                 | inc                 esp
            //   488b442450           | mov                 edi, dword ptr [ebx + 0x18]

        $sequence_4 = { ffd6 41b804010000 488d0d983e0000 488d94249c020000 ffd6 488d442470 4531c0 }
            // n = 7, score = 100
            //   ffd6                 | mov                 eax, dword ptr [esp + 0x58]
            //   41b804010000         | dec                 eax
            //   488d0d983e0000       | mov                 ecx, dword ptr [eax]
            //   488d94249c020000     | dec                 eax
            //   ffd6                 | mov                 eax, dword ptr [esp + 0x58]
            //   488d442470           | dec                 eax
            //   4531c0               | mov                 ecx, dword ptr [eax + 8]

        $sequence_5 = { 488d942410080000 4889d9 e8???????? 85c0 75ad 4889d9 ff15???????? }
            // n = 7, score = 100
            //   488d942410080000     | dec                 ebp
            //   4889d9               | test                esi, esi
            //   e8????????           |                     
            //   85c0                 | je                  0x16a3
            //   75ad                 | dec                 eax
            //   4889d9               | test                eax, eax
            //   ff15????????         |                     

        $sequence_6 = { 4989d8 488d9424b0130000 e8???????? 488d8c24ac120000 ff15???????? 4d89e1 4c8d0534680000 }
            // n = 7, score = 100
            //   4989d8               | cmp                 eax, -1
            //   488d9424b0130000     | je                  0x1abe
            //   e8????????           |                     
            //   488d8c24ac120000     | dec                 eax
            //   ff15????????         |                     
            //   4d89e1               | xchg                eax, ebx
            //   4c8d0534680000       | push                2

        $sequence_7 = { 4889d9 e8???????? 488d15eb8b0000 4989f0 4889d1 e8???????? 488d0dd98b0000 }
            // n = 7, score = 100
            //   4889d9               | test                byte ptr [eax + ecx*4], ah
            //   e8????????           |                     
            //   488d15eb8b0000       | add                 eax, 0x8d480000
            //   4989f0               | test                byte ptr [eax + edi*2], ah
            //   4889d1               | add                 al, 0
            //   e8????????           |                     
            //   488d0dd98b0000       | add                 byte ptr [eax - 0x77], cl

        $sequence_8 = { 488d0ddb390000 ffd5 488d0dda390000 488906 ffd5 488d0dce390000 48894608 }
            // n = 7, score = 100
            //   488d0ddb390000       | mov                 edx, dword ptr [esp + 0x80]
            //   ffd5                 | inc                 esp
            //   488d0dda390000       | mov                 ecx, dword ptr [esp + 0x4c]
            //   488906               | dec                 esp
            //   ffd5                 | mov                 ebx, dword ptr [esp + 0x88]
            //   488d0dce390000       | test                ecx, ecx
            //   48894608             | jne                 0x1f64

        $sequence_9 = { ff15???????? 4883660800 488906 4883661000 eb8e 83a424e00e000000 488d9424e00e0000 }
            // n = 7, score = 100
            //   ff15????????         |                     
            //   4883660800           | jne                 0x803
            //   488906               | dec                 eax
            //   4883661000           | test                edx, edx
            //   eb8e                 | jne                 0x9bb
            //   83a424e00e000000     | dec                 eax
            //   488d9424e00e0000     | mov                 eax, dword ptr [esp + 0x90]

    condition:
        7 of them and filesize < 238592
}