rule win_katz_stealer_auto {

    meta:
        author = "Felix Bilstein - yara-signator at cocacoding dot com"
        date = "2026-05-04"
        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 = "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 = { 4d85db 0f8473feffff 48c744245801000000 4b8d445afe 31d2 4889442450 668910 }
            // n = 7, score = 100
            //   4d85db               | mov                 byte ptr [ecx], al
            //   0f8473feffff         | dec                 ecx
            //   48c744245801000000     | add    eax, 1
            //   4b8d445afe           | dec                 eax
            //   31d2                 | sub                 edx, 1
            //   4889442450           | jne                 0x17d
            //   668910               | test                al, al

        $sequence_1 = { 488d8c2448020000 e8???????? 4885c0 0f845e010000 4896 488d442438 41b919000200 }
            // n = 7, score = 100
            //   488d8c2448020000     | dec                 esp
            //   e8????????           |                     
            //   4885c0               | lea                 ecx, [esp + 0x468]
            //   0f845e010000         | dec                 eax
            //   4896                 | mov                 dword ptr [esp + 0x20], eax
            //   488d442438           | jmp                 0x3c3
            //   41b919000200         | dec                 eax

        $sequence_2 = { 4c8d05f6ae0000 5a 4889e9 e8???????? 4889e9 ff15???????? }
            // n = 6, score = 100
            //   4c8d05f6ae0000       | test                eax, eax
            //   5a                   | je                  0xfb6
            //   4889e9               | dec                 eax
            //   e8????????           |                     
            //   4889e9               | cmp                 dword ptr [esp + 0x40], 0
            //   ff15????????         |                     

        $sequence_3 = { 4885f6 7450 488b8c24780c0000 e8???????? 488364242000 4889f2 }
            // n = 6, score = 100
            //   4885f6               | mov                 eax, dword ptr [ebx + 8]
            //   7450                 | mov                 edx, 0x104
            //   488b8c24780c0000     | dec                 eax
            //   e8????????           |                     
            //   488364242000         | lea                 ecx, [esp + 0xac]
            //   4889f2               | dec                 eax

        $sequence_4 = { 488d152d880000 4c89f9 e8???????? 85c0 0f85e9040000 4c8d05a2880000 ba04010000 }
            // n = 7, score = 100
            //   488d152d880000       | mov                 ecx, esp
            //   4c89f9               | dec                 eax
            //   e8????????           |                     
            //   85c0                 | lea                 edx, [esp + 0xba8]
            //   0f85e9040000         | dec                 eax
            //   4c8d05a2880000       | mov                 ecx, esi
            //   ba04010000           | call                dword ptr [esp + 0x58]

        $sequence_5 = { 488d15a1690000 488d8c2474040000 e8???????? 4897 4885ff 7454 4889fa }
            // n = 7, score = 100
            //   488d15a1690000       | lea                 esp, [0x93b1]
            //   488d8c2474040000     | test                eax, eax
            //   e8????????           |                     
            //   4897                 | je                  0xdda
            //   4885ff               | dec                 eax
            //   7454                 | lea                 edx, [0x8a89]
            //   4889fa               | dec                 esp

        $sequence_6 = { 488b05???????? 4889442448 f68424c005000010 0f85c6000000 4c8dbc24ec050000 4c8d8c24ac000000 ba04010000 }
            // n = 7, score = 100
            //   488b05????????       |                     
            //   4889442448           | lea                 edx, [0x85a6]
            //   f68424c005000010     | mov                 byte ptr [esp + eax + 0xfb0], 0
            //   0f85c6000000         | xor                 ecx, ecx
            //   4c8dbc24ec050000     | dec                 eax
            //   4c8d8c24ac000000     | cwde                
            //   ba04010000           | dec                 eax

        $sequence_7 = { 4c8b442460 ba08020000 488d8c2410080000 ffd6 488b442468 488364243800 4531c9 }
            // n = 7, score = 100
            //   4c8b442460           | dec                 eax
            //   ba08020000           | mov                 dword ptr [esi], edx
            //   488d8c2410080000     | dec                 eax
            //   ffd6                 | add                 esp, 0x58
            //   488b442468           | je                  0x1ef1
            //   488364243800         | dec                 eax
            //   4531c9               | mov                 edx, dword ptr [esp + 0x48]

        $sequence_8 = { 410fb701 6685c0 75d0 41f7c300020000 0f85bb010000 31c9 48895c2470 }
            // n = 7, score = 100
            //   410fb701             | cmp                 byte ptr [esp + 0x170], 0x5b
            //   6685c0               | jne                 0x36b
            //   75d0                 | cmp                 byte ptr [esp + 0x70], 0
            //   41f7c300020000       | je                  0x36b
            //   0f85bb010000         | dec                 eax
            //   31c9                 | mov                 ecx, edi
            //   48895c2470           | test                eax, eax

        $sequence_9 = { 4531c9 488b2d???????? 4889f1 4158 }
            // n = 4, score = 100
            //   4531c9               | lea                 eax, [eax + ebx*2 - 2]
            //   488b2d????????       |                     
            //   4889f1               | inc                 ecx
            //   4158                 | and                 eax, 1

    condition:
        7 of them and filesize < 238592
}