rule win_valkyrie_stealer_auto {

    meta:
        author = "Felix Bilstein - yara-signator at cocacoding dot com"
        date = "2026-09-17"
        version = "1"
        description = "Detects win.valkyrie_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.valkyrie_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 = { 85c0 0f8486000000 488b5d48 4533c9 418b8590000000 ba0b000000 ffc0 }
            // n = 7, score = 100
            //   85c0                 | dec                 eax
            //   0f8486000000         | mov                 ebx, dword ptr [ecx]
            //   488b5d48             | dec                 eax
            //   4533c9               | mov                 esi, ecx
            //   418b8590000000       | jbe                 0x93
            //   ba0b000000           | cmp                 byte ptr [ebx + 0xc5], 0
            //   ffc0                 | je                  0x41

        $sequence_1 = { 7423 8bc8 410fb600 0fb68438500c1200 388439500c1200 750c 49ffc1 }
            // n = 7, score = 100
            //   7423                 | dec                 ecx
            //   8bc8                 | mov                 ecx, esi
            //   410fb600             | dec                 eax
            //   0fb68438500c1200     | lea                 edx, [0x116cab]
            //   388439500c1200       | dec                 eax
            //   750c                 | cmp                 dword ptr [eax + 0x18], 0xf
            //   49ffc1               | jbe                 0x171d

        $sequence_2 = { e8???????? 448b4ddc eb2a 8d4101 418907 488d0c49 488b8388000000 }
            // n = 7, score = 100
            //   e8????????           |                     
            //   448b4ddc             | xor                 esi, esi
            //   eb2a                 | dec                 eax
            //   8d4101               | mov                 ebp, 0x45d1745d
            //   418907               | pop                 ss
            //   488d0c49             | pop                 ebp
            //   488b8388000000       | je                  0x16cf

        $sequence_3 = { ba71000000 c744242803000000 488bcb 89742420 e8???????? 488d9388000000 eb3c }
            // n = 7, score = 100
            //   ba71000000           | mov                 dword ptr [esp + 0x20], eax
            //   c744242803000000     | mov                 edx, 0x40000000
            //   488bcb               | dec                 eax
            //   89742420             | cmp                 eax, -1
            //   e8????????           |                     
            //   488d9388000000       | dec                 eax
            //   eb3c                 | lea                 ecx, [0xfffb74e7]

        $sequence_4 = { 8b7c2454 4183ffff 4c8b7c2468 b801000000 8b6c2444 400fb6ff 0f44f8 }
            // n = 7, score = 100
            //   8b7c2454             | dec                 eax
            //   4183ffff             | add                 esp, 0x60
            //   4c8b7c2468           | inc                 ecx
            //   b801000000           | pop                 esi
            //   8b6c2444             | ret                 
            //   400fb6ff             | dec                 eax
            //   0f44f8               | mov                 dword ptr [esp + 8], ebx

        $sequence_5 = { 8bc3 83e00f ffc3 884c0420 84c9 78d3 488bd6 }
            // n = 7, score = 100
            //   8bc3                 | mov                 dword ptr [esp + 0x40], esi
            //   83e00f               | dec                 eax
            //   ffc3                 | mov                 edx, dword ptr [ebp + 0xa0]
            //   884c0420             | dec                 eax
            //   84c9                 | mov                 eax, dword ptr [esp + 0x40]
            //   78d3                 | dec                 eax
            //   488bd6               | mov                 ecx, ebx

        $sequence_6 = { e8???????? 89442440 448bd8 85c0 0f8481030000 8b44243c 4103c3 }
            // n = 7, score = 100
            //   e8????????           |                     
            //   89442440             | inc                 edx
            //   448bd8               | mov                 cl, byte ptr [ecx + ebx + 0x12c980]
            //   85c0                 | dec                 eax
            //   0f8481030000         | sub                 edx, eax
            //   8b44243c             | dec                 ecx
            //   4103c3               | mov                 dword ptr [ecx + 0x10], edx

        $sequence_7 = { e9???????? 488b4210 f20f1010 66490f7ed0 488d15c2cc0600 488d4dc0 e8???????? }
            // n = 7, score = 100
            //   e9????????           |                     
            //   488b4210             | inc                 ecx
            //   f20f1010             | mov                 edx, esp
            //   66490f7ed0           | dec                 ecx
            //   488d15c2cc0600       | mov                 edi, dword ptr [esp + 0x260]
            //   488d4dc0             | dec                 eax
            //   e8????????           |                     

        $sequence_8 = { 7e31 488d1500290d00 488bce e8???????? eb20 4d85f6 740b }
            // n = 7, score = 100
            //   7e31                 | test                eax, eax
            //   488d1500290d00       | dec                 eax
            //   488bce               | mov                 dword ptr [ebp - 0x28], eax
            //   e8????????           |                     
            //   eb20                 | movups              xmm0, xmmword ptr [ebp - 0x30]
            //   4d85f6               | movups              xmmword ptr [edx], xmm0
            //   740b                 | xor                 al, al

        $sequence_9 = { 41855724 0f847d010000 49837f1000 0f8437010000 6685d3 0f852e010000 498b0424 }
            // n = 7, score = 100
            //   41855724             | mov                 eax, dword ptr [ebp - 0x49]
            //   0f847d010000         | and                 esi, 3
            //   49837f1000           | test                eax, eax
            //   0f8437010000         | je                  0xf35
            //   6685d3               | jl                  0xefa
            //   0f852e010000         | inc                 esp
            //   498b0424             | mov                 dword ptr [esp + 0x40], ecx

    condition:
        7 of them and filesize < 2895872
}