rule win_deltastealer_auto {

    meta:
        author = "Felix Bilstein - yara-signator at cocacoding dot com"
        date = "2026-05-04"
        version = "1"
        description = "Detects win.deltastealer."
        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.deltastealer"
        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 = { 4885c0 7807 4801c6 720d eb34 4889c1 48f7d9 }
            // n = 7, score = 200
            //   4885c0               | mov                 dword ptr [esp + 0x20], edx
            //   7807                 | mov                 byte ptr [esp + 0x90], 2
            //   4801c6               | dec                 eax
            //   720d                 | mov                 dword ptr [esp + 0x98], esi
            //   eb34                 | cmp                 byte ptr [esi + 0x68], 2
            //   4889c1               | dec                 eax
            //   48f7d9               | test                eax, eax

        $sequence_1 = { c3 31ff eb0c 31ff b301 eb06 b302 }
            // n = 7, score = 200
            //   c3                   | movzx               edi, word ptr [esp + 0x78]
            //   31ff                 | movzx               ebx, word ptr [esp + 0x7a]
            //   eb0c                 | inc                 esp
            //   31ff                 | mov                 esp, dword ptr [esp + 0x7c]
            //   b301                 | inc                 esp
            //   eb06                 | mov                 eax, dword ptr [esp + 0x80]
            //   b302                 | shr                 edx, 9

        $sequence_2 = { 4c89f9 ba3a000000 ffd3 84c0 0f850a010000 4c896c2478 4c89b42480000000 }
            // n = 7, score = 200
            //   4c89f9               | mov                 al, 1
            //   ba3a000000           | dec                 eax
            //   ffd3                 | test                eax, eax
            //   84c0                 | dec                 esp
            //   0f850a010000         | mov                 ecx, edi
            //   4c896c2478           | dec                 esp
            //   4c89b42480000000     | mov                 edx, esp

        $sequence_3 = { 488b4c2440 8b3481 48ffc0 49c7467001000000 49894678 eb33 4983661800 }
            // n = 7, score = 200
            //   488b4c2440           | mov                 dword ptr [esp + 0x38], edx
            //   8b3481               | dec                 eax
            //   48ffc0               | mov                 dword ptr [ebp - 0x50], edx
            //   49c7467001000000     | dec                 eax
            //   49894678             | mov                 ecx, dword ptr [esp + 0x40]
            //   eb33                 | dec                 eax
            //   4983661800           | mov                 edx, ebx

        $sequence_4 = { e8???????? 84c0 0f840effffff e9???????? b301 48833f00 7588 }
            // n = 7, score = 200
            //   e8????????           |                     
            //   84c0                 | mov                 edx, edi
            //   0f840effffff         | and                 dword ptr [esi + 0xc8], 0
            //   e9????????           |                     
            //   b301                 | inc                 ebp
            //   48833f00             | xor                 esp, esp
            //   7588                 | xor                 edi, edi

        $sequence_5 = { e8???????? 48033e 48897c2428 483b7e08 770e 48893e 4881c480000000 }
            // n = 7, score = 200
            //   e8????????           |                     
            //   48033e               | mov                 esi, dword ptr [ebp + 0x2a8]
            //   48897c2428           | inc                 ecx
            //   483b7e08             | lea                 edi, [esi + 1]
            //   770e                 | dec                 eax
            //   48893e               | mov                 eax, esi
            //   4881c480000000       | dec                 eax

        $sequence_6 = { 785c 4983faff 74e6 4489d7 29c7 83e707 75dc }
            // n = 7, score = 200
            //   785c                 | sub                 ecx, edx
            //   4983faff             | dec                 eax
            //   74e6                 | cmp                 ecx, 0x81
            //   4489d7               | jae                 0x2d9
            //   29c7                 | dec                 esp
            //   83e707               | mov                 dword ptr [esp + 0x28], edx
            //   75dc                 | dec                 esp

        $sequence_7 = { 4c89e9 4d89e0 e8???????? eb81 48c1ef39 488d43f0 4821c5 }
            // n = 7, score = 200
            //   4c89e9               | dec                 eax
            //   4d89e0               | mov                 edx, esi
            //   e8????????           |                     
            //   eb81                 | dec                 ecx
            //   48c1ef39             | mov                 eax, eax
            //   488d43f0             | test                al, al
            //   4821c5               | jne                 0x63a

        $sequence_8 = { 83be9000000004 7479 e9???????? 4885c0 0f8588000000 488b8690000000 4883f803 }
            // n = 7, score = 200
            //   83be9000000004       | dec                 eax
            //   7479                 | mov                 ecx, dword ptr [esi + 0x28]
            //   e9????????           |                     
            //   4885c0               | dec                 eax
            //   0f8588000000         | mov                 edi, eax
            //   488b8690000000       | dec                 ecx
            //   4883f803             | mov                 esp, edx

        $sequence_9 = { 5f 5e e9???????? 8a0f 4889f2 4883c428 5f }
            // n = 7, score = 200
            //   5f                   | xor                 ecx, ecx
            //   5e                   | pop                 edi
            //   e9????????           |                     
            //   8a0f                 | pop                 esi
            //   4889f2               | ret                 
            //   4883c428             | dec                 eax
            //   5f                   | add                 ecx, 0x10

    condition:
        7 of them and filesize < 3532800
}