rule win_ratankbapos_auto {

    meta:
        author = "Felix Bilstein - yara-signator at cocacoding dot com"
        date = "2026-09-17"
        version = "1"
        description = "Detects win.ratankbapos."
        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.ratankbapos"
        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 = { 751c c74314ffffffff 5f 5e 33c0 5b 8b4dfc }
            // n = 7, score = 300
            //   751c                 | jne                 0x1e
            //   c74314ffffffff       | mov                 dword ptr [ebx + 0x14], 0xffffffff
            //   5f                   | pop                 edi
            //   5e                   | pop                 esi
            //   33c0                 | xor                 eax, eax
            //   5b                   | pop                 ebx
            //   8b4dfc               | mov                 ecx, dword ptr [ebp - 4]

        $sequence_1 = { 8bc8 c1f905 83e01f c1e006 8b0c8de04d0110 }
            // n = 5, score = 300
            //   8bc8                 | mov                 ecx, eax
            //   c1f905               | sar                 ecx, 5
            //   83e01f               | and                 eax, 0x1f
            //   c1e006               | shl                 eax, 6
            //   8b0c8de04d0110       | mov                 ecx, dword ptr [ecx*4 + 0x10014de0]

        $sequence_2 = { 51 68ff1f0000 8d95fcdfffff 89430c 8b4304 }
            // n = 5, score = 300
            //   51                   | push                ecx
            //   68ff1f0000           | push                0x1fff
            //   8d95fcdfffff         | lea                 edx, [ebp - 0x2004]
            //   89430c               | mov                 dword ptr [ebx + 0xc], eax
            //   8b4304               | mov                 eax, dword ptr [ebx + 4]

        $sequence_3 = { 8d8df8dfffff 51 68ff1f0000 8d95fcdfffff 89430c }
            // n = 5, score = 300
            //   8d8df8dfffff         | lea                 ecx, [ebp - 0x2008]
            //   51                   | push                ecx
            //   68ff1f0000           | push                0x1fff
            //   8d95fcdfffff         | lea                 edx, [ebp - 0x2004]
            //   89430c               | mov                 dword ptr [ebx + 0xc], eax

        $sequence_4 = { e8???????? 8b4510 33c9 8a4801 8d14cdd8ea0010 }
            // n = 5, score = 300
            //   e8????????           |                     
            //   8b4510               | mov                 eax, dword ptr [ebp + 0x10]
            //   33c9                 | xor                 ecx, ecx
            //   8a4801               | mov                 cl, byte ptr [eax + 1]
            //   8d14cdd8ea0010       | lea                 edx, [ecx*8 + 0x1000ead8]

        $sequence_5 = { 8945e0 33f6 8b0d???????? 3bf1 0f8d2e010000 8b1cf5504a0110 }
            // n = 6, score = 300
            //   8945e0               | mov                 dword ptr [ebp - 0x20], eax
            //   33f6                 | xor                 esi, esi
            //   8b0d????????         |                     
            //   3bf1                 | cmp                 esi, ecx
            //   0f8d2e010000         | jge                 0x134
            //   8b1cf5504a0110       | mov                 ebx, dword ptr [esi*8 + 0x10014a50]

        $sequence_6 = { 837d0cff 8b4508 56 57 8945b8 750f }
            // n = 6, score = 300
            //   837d0cff             | cmp                 dword ptr [ebp + 0xc], -1
            //   8b4508               | mov                 eax, dword ptr [ebp + 8]
            //   56                   | push                esi
            //   57                   | push                edi
            //   8945b8               | mov                 dword ptr [ebp - 0x48], eax
            //   750f                 | jne                 0x11

        $sequence_7 = { 8bc2 c78574ffffff3c000000 89b578ffffff 89b57cffffff 897584 66894d8c }
            // n = 6, score = 300
            //   8bc2                 | mov                 eax, edx
            //   c78574ffffff3c000000     | mov    dword ptr [ebp - 0x8c], 0x3c
            //   89b578ffffff         | mov                 dword ptr [ebp - 0x88], esi
            //   89b57cffffff         | mov                 dword ptr [ebp - 0x84], esi
            //   897584               | mov                 dword ptr [ebp - 0x7c], esi
            //   66894d8c             | mov                 word ptr [ebp - 0x74], cx

        $sequence_8 = { 6803010000 8d44242d 53 50 885c2434 e8???????? 6803010000 }
            // n = 7, score = 300
            //   6803010000           | push                0x103
            //   8d44242d             | lea                 eax, [esp + 0x2d]
            //   53                   | push                ebx
            //   50                   | push                eax
            //   885c2434             | mov                 byte ptr [esp + 0x34], bl
            //   e8????????           |                     
            //   6803010000           | push                0x103

        $sequence_9 = { e8???????? 8b5d0c 83c40c 6800100000 }
            // n = 4, score = 300
            //   e8????????           |                     
            //   8b5d0c               | mov                 ebx, dword ptr [ebp + 0xc]
            //   83c40c               | add                 esp, 0xc
            //   6800100000           | push                0x1000

    condition:
        7 of them and filesize < 327680
}

rule win_ratankbapos_w0 {
    meta:
        author = "Threat Exchange http://blog.trex.re.kr/3"
        description = "hkp.dll"
        malpedia_reference = "https://malpedia.caad.fkie.fraunhofer.de/details/win.ratankbapos"
        malpedia_version = "20180613"
        malpedia_license = "CC BY-NC-SA 4.0"
        malpedia_sharing = "TLP:WHITE"
    strings:
        $dll = "ksnetadsl.dll" ascii wide fullword nocase
        $exe = "xplatform.exe" ascii wide fullword nocase
        $agent = "Nimo Software HTTP Retriever 1.0" ascii wide nocase 
        $log_file = "c:\\windows\\temp\\log.tmp" ascii wide nocase 
        $base_addr = "%d-BaseAddr:0x%x" ascii wide nocase
        $func_addr = "%d-FuncAddr:0x%x" ascii wide nocase
        $HF_S = "HF-S(%d)" ascii wide
        $HF_T = "HF-T(%d)" ascii wide
    condition:
        5 of them
}

rule win_ratankbapos_w1 {
    meta:
        author = "Threat Exchange http://blog.trex.re.kr/3"
        malpedia_reference = "https://malpedia.caad.fkie.fraunhofer.de/details/win.ratankbapos"
        malpedia_version = "20180613"
        malpedia_license = "CC BY-NC-SA 4.0"
        malpedia_sharing = "TLP:WHITE"
    strings:
        $cardinfo_parsing = {6A 25 83 ?? F0}
        $subs_table = { 5A 43 4B 4F [6] 41 44 42 4C [7] 4E 58 [6] 59}
    condition:
        all of them
}