rule win_stealer_0x3401_auto {

    meta:
        author = "Felix Bilstein - yara-signator at cocacoding dot com"
        date = "2026-05-04"
        version = "1"
        description = "Detects win.stealer_0x3401."
        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.stealer_0x3401"
        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 = { e8???????? c745fcffffffff 8b45bc 83f810 7242 8b4da8 40 }
            // n = 7, score = 100
            //   e8????????           |                     
            //   c745fcffffffff       | mov                 dword ptr [ebp - 4], 0xffffffff
            //   8b45bc               | mov                 eax, dword ptr [ebp - 0x44]
            //   83f810               | cmp                 eax, 0x10
            //   7242                 | jb                  0x44
            //   8b4da8               | mov                 ecx, dword ptr [ebp - 0x58]
            //   40                   | inc                 eax

        $sequence_1 = { 8b8510ffffff 85c0 7473 50 8d4dbc e8???????? 8bd0 }
            // n = 7, score = 100
            //   8b8510ffffff         | mov                 eax, dword ptr [ebp - 0xf0]
            //   85c0                 | test                eax, eax
            //   7473                 | je                  0x75
            //   50                   | push                eax
            //   8d4dbc               | lea                 ecx, [ebp - 0x44]
            //   e8????????           |                     
            //   8bd0                 | mov                 edx, eax

        $sequence_2 = { 8bc8 51 e8???????? 83c404 6a54 68???????? }
            // n = 6, score = 100
            //   8bc8                 | mov                 ecx, eax
            //   51                   | push                ecx
            //   e8????????           |                     
            //   83c404               | add                 esp, 4
            //   6a54                 | push                0x54
            //   68????????           |                     

        $sequence_3 = { 68???????? b9???????? e8???????? e9???????? 83fe03 0f87e3000000 ff24b55c3e0010 }
            // n = 7, score = 100
            //   68????????           |                     
            //   b9????????           |                     
            //   e8????????           |                     
            //   e9????????           |                     
            //   83fe03               | cmp                 esi, 3
            //   0f87e3000000         | ja                  0xe9
            //   ff24b55c3e0010       | jmp                 dword ptr [esi*4 + 0x10003e5c]

        $sequence_4 = { 8b06 894714 c70607000000 833e08 c746fc00000000 7205 8b46ec }
            // n = 7, score = 100
            //   8b06                 | mov                 eax, dword ptr [esi]
            //   894714               | mov                 dword ptr [edi + 0x14], eax
            //   c70607000000         | mov                 dword ptr [esi], 7
            //   833e08               | cmp                 dword ptr [esi], 8
            //   c746fc00000000       | mov                 dword ptr [esi - 4], 0
            //   7205                 | jb                  7
            //   8b46ec               | mov                 eax, dword ptr [esi - 0x14]

        $sequence_5 = { 731f 8bc1 83e13f c1f806 6bc930 8b0485c8710210 f644082801 }
            // n = 7, score = 100
            //   731f                 | jae                 0x21
            //   8bc1                 | mov                 eax, ecx
            //   83e13f               | and                 ecx, 0x3f
            //   c1f806               | sar                 eax, 6
            //   6bc930               | imul                ecx, ecx, 0x30
            //   8b0485c8710210       | mov                 eax, dword ptr [eax*4 + 0x100271c8]
            //   f644082801           | test                byte ptr [eax + ecx + 0x28], 1

        $sequence_6 = { c745e800000000 668945d8 663902 741d 8bc2 8d7802 }
            // n = 6, score = 100
            //   c745e800000000       | mov                 dword ptr [ebp - 0x18], 0
            //   668945d8             | mov                 word ptr [ebp - 0x28], ax
            //   663902               | cmp                 word ptr [edx], ax
            //   741d                 | je                  0x1f
            //   8bc2                 | mov                 eax, edx
            //   8d7802               | lea                 edi, [eax + 2]

        $sequence_7 = { c745fc04000000 e8???????? 8b45a4 83f810 7242 8b4d90 }
            // n = 6, score = 100
            //   c745fc04000000       | mov                 dword ptr [ebp - 4], 4
            //   e8????????           |                     
            //   8b45a4               | mov                 eax, dword ptr [ebp - 0x5c]
            //   83f810               | cmp                 eax, 0x10
            //   7242                 | jb                  0x44
            //   8b4d90               | mov                 ecx, dword ptr [ebp - 0x70]

        $sequence_8 = { 50 8d45f4 64a300000000 8d8580fdffff c7857cfdffff00000000 50 ff15???????? }
            // n = 7, score = 100
            //   50                   | push                eax
            //   8d45f4               | lea                 eax, [ebp - 0xc]
            //   64a300000000         | mov                 dword ptr fs:[0], eax
            //   8d8580fdffff         | lea                 eax, [ebp - 0x280]
            //   c7857cfdffff00000000     | mov    dword ptr [ebp - 0x284], 0
            //   50                   | push                eax
            //   ff15????????         |                     

        $sequence_9 = { c70300000000 8b4310 894610 8b4314 894614 c7431407000000 837b1408 }
            // n = 7, score = 100
            //   c70300000000         | mov                 dword ptr [ebx], 0
            //   8b4310               | mov                 eax, dword ptr [ebx + 0x10]
            //   894610               | mov                 dword ptr [esi + 0x10], eax
            //   8b4314               | mov                 eax, dword ptr [ebx + 0x14]
            //   894614               | mov                 dword ptr [esi + 0x14], eax
            //   c7431407000000       | mov                 dword ptr [ebx + 0x14], 7
            //   837b1408             | cmp                 dword ptr [ebx + 0x14], 8

    condition:
        7 of them and filesize < 357376
}