rule win_fickerstealer_auto {

    meta:
        author = "Felix Bilstein - yara-signator at cocacoding dot com"
        date = "2021-06-10"
        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 = "20210604"
        malpedia_hash = "be09d5d71e77373c0f538068be31a2ad4c69cfbd"
        malpedia_version = "20210616"
        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???????? ebcb e8???????? 83f812 750c 8b442404 c70002000000 }
            // n = 7, score = 100
            //   e8????????           |                     
            //   ebcb                 | jmp                 0xffffffcd
            //   e8????????           |                     
            //   83f812               | cmp                 eax, 0x12
            //   750c                 | jne                 0xe
            //   8b442404             | mov                 eax, dword ptr [esp + 4]
            //   c70002000000         | mov                 dword ptr [eax], 2

        $sequence_1 = { ebdc 6a08 5e 6afc 5b 6a03 5f }
            // n = 7, score = 100
            //   ebdc                 | jmp                 0xffffffde
            //   6a08                 | push                8
            //   5e                   | pop                 esi
            //   6afc                 | push                -4
            //   5b                   | pop                 ebx
            //   6a03                 | push                3
            //   5f                   | pop                 edi

        $sequence_2 = { e9???????? 85d2 751d 8b481c 6a02 68???????? ff7018 }
            // n = 7, score = 100
            //   e9????????           |                     
            //   85d2                 | test                edx, edx
            //   751d                 | jne                 0x1f
            //   8b481c               | mov                 ecx, dword ptr [eax + 0x1c]
            //   6a02                 | push                2
            //   68????????           |                     
            //   ff7018               | push                dword ptr [eax + 0x18]

        $sequence_3 = { f20f1100 31c0 40 50 e8???????? 58 8d4dd4 }
            // n = 7, score = 100
            //   f20f1100             | movsd               qword ptr [eax], xmm0
            //   31c0                 | xor                 eax, eax
            //   40                   | inc                 eax
            //   50                   | push                eax
            //   e8????????           |                     
            //   58                   | pop                 eax
            //   8d4dd4               | lea                 ecx, dword ptr [ebp - 0x2c]

        $sequence_4 = { 89de 89c3 8911 897904 8dbc24f0010000 89f9 ff7610 }
            // n = 7, score = 100
            //   89de                 | mov                 esi, ebx
            //   89c3                 | mov                 ebx, eax
            //   8911                 | mov                 dword ptr [ecx], edx
            //   897904               | mov                 dword ptr [ecx + 4], edi
            //   8dbc24f0010000       | lea                 edi, dword ptr [esp + 0x1f0]
            //   89f9                 | mov                 ecx, edi
            //   ff7610               | push                dword ptr [esi + 0x10]

        $sequence_5 = { e9???????? 89742418 89fe eb42 83a4248000000000 89c2 8d842480000000 }
            // n = 7, score = 100
            //   e9????????           |                     
            //   89742418             | mov                 dword ptr [esp + 0x18], esi
            //   89fe                 | mov                 esi, edi
            //   eb42                 | jmp                 0x44
            //   83a4248000000000     | and                 dword ptr [esp + 0x80], 0
            //   89c2                 | mov                 edx, eax
            //   8d842480000000       | lea                 eax, dword ptr [esp + 0x80]

        $sequence_6 = { 5a e8???????? 89c3 6a19 59 89c7 f3a5 }
            // n = 7, score = 100
            //   5a                   | pop                 edx
            //   e8????????           |                     
            //   89c3                 | mov                 ebx, eax
            //   6a19                 | push                0x19
            //   59                   | pop                 ecx
            //   89c7                 | mov                 edi, eax
            //   f3a5                 | rep movsd           dword ptr es:[edi], dword ptr [esi]

        $sequence_7 = { e8???????? e9???????? c744244c00000000 e9???????? f20f108424ac0a0000 f20f1094249c0a0000 f20f108c24a40a0000 }
            // n = 7, score = 100
            //   e8????????           |                     
            //   e9????????           |                     
            //   c744244c00000000     | mov                 dword ptr [esp + 0x4c], 0
            //   e9????????           |                     
            //   f20f108424ac0a0000     | movsd    xmm0, qword ptr [esp + 0xaac]
            //   f20f1094249c0a0000     | movsd    xmm2, qword ptr [esp + 0xa9c]
            //   f20f108c24a40a0000     | movsd    xmm1, qword ptr [esp + 0xaa4]

        $sequence_8 = { f30f110424 89442404 e8???????? 83c408 5d c3 55 }
            // n = 7, score = 100
            //   f30f110424           | movss               dword ptr [esp], xmm0
            //   89442404             | mov                 dword ptr [esp + 4], eax
            //   e8????????           |                     
            //   83c408               | add                 esp, 8
            //   5d                   | pop                 ebp
            //   c3                   | ret                 
            //   55                   | push                ebp

        $sequence_9 = { 21c7 21c1 8d8558ffffff f20f1000 f20f104808 034dc0 8d45e4 }
            // n = 7, score = 100
            //   21c7                 | and                 edi, eax
            //   21c1                 | and                 ecx, eax
            //   8d8558ffffff         | lea                 eax, dword ptr [ebp - 0xa8]
            //   f20f1000             | movsd               xmm0, qword ptr [eax]
            //   f20f104808           | movsd               xmm1, qword ptr [eax + 8]
            //   034dc0               | add                 ecx, dword ptr [ebp - 0x40]
            //   8d45e4               | lea                 eax, dword ptr [ebp - 0x1c]

    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
}