rule win_fickerstealer_auto {

    meta:
        author = "Felix Bilstein - yara-signator at cocacoding dot com"
        date = "2023-12-06"
        version = "1"
        description = "Detects win.fickerstealer."
        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.fickerstealer"
        malpedia_rule_date = "20231130"
        malpedia_hash = "fc8a0e9f343f6d6ded9e7df1a64dac0cc68d7351"
        malpedia_version = "20230808"
        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 = { 8b55c8 897150 895154 8b75cc 8b55d0 897158 89515c }
            // n = 7, score = 200
            //   8b55c8               | mov                 edx, dword ptr [ebp - 0x38]
            //   897150               | mov                 dword ptr [ecx + 0x50], esi
            //   895154               | mov                 dword ptr [ecx + 0x54], edx
            //   8b75cc               | mov                 esi, dword ptr [ebp - 0x34]
            //   8b55d0               | mov                 edx, dword ptr [ebp - 0x30]
            //   897158               | mov                 dword ptr [ecx + 0x58], esi
            //   89515c               | mov                 dword ptr [ecx + 0x5c], edx

        $sequence_1 = { ba???????? 0f2840f0 0f2808 0f298424a0040000 0f294910 0f2901 6a00 }
            // n = 7, score = 200
            //   ba????????           |                     
            //   0f2840f0             | movaps              xmm0, xmmword ptr [eax - 0x10]
            //   0f2808               | movaps              xmm1, xmmword ptr [eax]
            //   0f298424a0040000     | movaps              xmmword ptr [esp + 0x4a0], xmm0
            //   0f294910             | movaps              xmmword ptr [ecx + 0x10], xmm1
            //   0f2901               | movaps              xmmword ptr [ecx], xmm0
            //   6a00                 | push                0

        $sequence_2 = { c1e104 85c0 f20f10840b90000000 f20f108c0b98000000 f20f118c2488000000 f20f11842480000000 f20f10442450 }
            // n = 7, score = 200
            //   c1e104               | shl                 ecx, 4
            //   85c0                 | test                eax, eax
            //   f20f10840b90000000     | movsd    xmm0, qword ptr [ebx + ecx + 0x90]
            //   f20f108c0b98000000     | movsd    xmm1, qword ptr [ebx + ecx + 0x98]
            //   f20f118c2488000000     | movsd    qword ptr [esp + 0x88], xmm1
            //   f20f11842480000000     | movsd    qword ptr [esp + 0x80], xmm0
            //   f20f10442450         | movsd               xmm0, qword ptr [esp + 0x50]

        $sequence_3 = { c1ea04 85d2 0f44d1 0f44f0 89d1 c1e902 6afe }
            // n = 7, score = 200
            //   c1ea04               | shr                 edx, 4
            //   85d2                 | test                edx, edx
            //   0f44d1               | cmove               edx, ecx
            //   0f44f0               | cmove               esi, eax
            //   89d1                 | mov                 ecx, edx
            //   c1e902               | shr                 ecx, 2
            //   6afe                 | push                -2

        $sequence_4 = { 8b3e e8???????? 84c0 7404 c6470401 8b06 8b08 }
            // n = 7, score = 200
            //   8b3e                 | mov                 edi, dword ptr [esi]
            //   e8????????           |                     
            //   84c0                 | test                al, al
            //   7404                 | je                  6
            //   c6470401             | mov                 byte ptr [edi + 4], 1
            //   8b06                 | mov                 eax, dword ptr [esi]
            //   8b08                 | mov                 ecx, dword ptr [eax]

        $sequence_5 = { 89d3 8954241c 897c2420 c744241801000000 89f1 e8???????? 3c0f }
            // n = 7, score = 200
            //   89d3                 | mov                 ebx, edx
            //   8954241c             | mov                 dword ptr [esp + 0x1c], edx
            //   897c2420             | mov                 dword ptr [esp + 0x20], edi
            //   c744241801000000     | mov                 dword ptr [esp + 0x18], 1
            //   89f1                 | mov                 ecx, esi
            //   e8????????           |                     
            //   3c0f                 | cmp                 al, 0xf

        $sequence_6 = { f20f114d9c f20f115594 7514 31d2 8d4ddc 42 e8???????? }
            // n = 7, score = 200
            //   f20f114d9c           | movsd               qword ptr [ebp - 0x64], xmm1
            //   f20f115594           | movsd               qword ptr [ebp - 0x6c], xmm2
            //   7514                 | jne                 0x16
            //   31d2                 | xor                 edx, edx
            //   8d4ddc               | lea                 ecx, [ebp - 0x24]
            //   42                   | inc                 edx
            //   e8????????           |                     

        $sequence_7 = { e9???????? 8d7c2448 89f9 e8???????? 833f01 0f85ed000000 }
            // n = 6, score = 200
            //   e9????????           |                     
            //   8d7c2448             | lea                 edi, [esp + 0x48]
            //   89f9                 | mov                 ecx, edi
            //   e8????????           |                     
            //   833f01               | cmp                 dword ptr [edi], 1
            //   0f85ed000000         | jne                 0xf3

        $sequence_8 = { 56 53 57 ff750c 50 e8???????? 83c424 }
            // n = 7, score = 200
            //   56                   | push                esi
            //   53                   | push                ebx
            //   57                   | push                edi
            //   ff750c               | push                dword ptr [ebp + 0xc]
            //   50                   | push                eax
            //   e8????????           |                     
            //   83c424               | add                 esp, 0x24

        $sequence_9 = { 898d40feffff 89f9 8985d4feffff 8b8570ffffff 8985d8feffff 8b4588 8985dcfeffff }
            // n = 7, score = 200
            //   898d40feffff         | mov                 dword ptr [ebp - 0x1c0], ecx
            //   89f9                 | mov                 ecx, edi
            //   8985d4feffff         | mov                 dword ptr [ebp - 0x12c], eax
            //   8b8570ffffff         | mov                 eax, dword ptr [ebp - 0x90]
            //   8985d8feffff         | mov                 dword ptr [ebp - 0x128], eax
            //   8b4588               | mov                 eax, dword ptr [ebp - 0x78]
            //   8985dcfeffff         | mov                 dword ptr [ebp - 0x124], eax

    condition:
        7 of them and filesize < 598016
}

rule win_fickerstealer_w0 {
  meta: 
    author = "Ben Cohen, CyberArk"
    date = "22-02-2021"
    version = "1.0"
    hash = "a4113ccb55e06e783b6cb213647614f039aa7dbb454baa338459ccf37897ebd6"
    source = "https://github.com/cyberark/malware-research/blob/master/FickerStealer/Ficker_Stealer.yar"
    description = "Yara rule for Ficker Stealer"
    malpedia_rule_date = "20210726"
    malpedia_hash = ""
    malpedia_version = "20210726"
    malpedia_license = "CC BY-NC-SA 4.0"
    malpedia_sharing = "TLP:WHITE"
    malpedia_reference = "https://malpedia.caad.fkie.fraunhofer.de/details/win.fickerstealer"
  
  strings:
    //$decryption_pattern = { 89 ?? C1 ?? ?? 31 ?? 89 ?? C1 ?? ?? 31 ?? 8B ?? ?? 89 ?? C1 ?? ?? 31 }
    $c2_const = { 0C 00 0F 0A [0-4] 0B 0A 0B 0A }

    $s1 = "kindmessage"
    $s2 = "SomeNone"
    $s3 = ".Kind"

  condition:
    //$decryption_pattern and
    $c2_const and
    (1 of ($s*)) and
    uint16(0) == 0x5A4D
}