rule win_fickerstealer_auto {

    meta:
        author = "Felix Bilstein - yara-signator at cocacoding dot com"
        date = "2022-11-21"
        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 = "20221118"
        malpedia_hash = "e0702e2e6d1d00da65c8a29a4ebacd0a4c59e1af"
        malpedia_version = "20221125"
        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 = { 8dbc24a0010000 8b72f8 89f9 e8???????? 8b3f 83ff02 7508 }
            // n = 7, score = 200
            //   8dbc24a0010000       | lea                 edi, [esp + 0x1a0]
            //   8b72f8               | mov                 esi, dword ptr [edx - 8]
            //   89f9                 | mov                 ecx, edi
            //   e8????????           |                     
            //   8b3f                 | mov                 edi, dword ptr [edi]
            //   83ff02               | cmp                 edi, 2
            //   7508                 | jne                 0xa

        $sequence_1 = { 8d7de0 89f9 e8???????? 89f0 e9???????? 0f0b 0f0b }
            // n = 7, score = 200
            //   8d7de0               | lea                 edi, [ebp - 0x20]
            //   89f9                 | mov                 ecx, edi
            //   e8????????           |                     
            //   89f0                 | mov                 eax, esi
            //   e9????????           |                     
            //   0f0b                 | ud2                 
            //   0f0b                 | ud2                 

        $sequence_2 = { 8b45ec c6400402 8d4dc4 c70001000000 e8???????? 83c460 }
            // n = 6, score = 200
            //   8b45ec               | mov                 eax, dword ptr [ebp - 0x14]
            //   c6400402             | mov                 byte ptr [eax + 4], 2
            //   8d4dc4               | lea                 ecx, [ebp - 0x3c]
            //   c70001000000         | mov                 dword ptr [eax], 1
            //   e8????????           |                     
            //   83c460               | add                 esp, 0x60

        $sequence_3 = { 50 51 52 ff751c ff7518 ff7514 ff7510 }
            // n = 7, score = 200
            //   50                   | push                eax
            //   51                   | push                ecx
            //   52                   | push                edx
            //   ff751c               | push                dword ptr [ebp + 0x1c]
            //   ff7518               | push                dword ptr [ebp + 0x18]
            //   ff7514               | push                dword ptr [ebp + 0x14]
            //   ff7510               | push                dword ptr [ebp + 0x10]

        $sequence_4 = { eb06 d3ea 89d0 31d2 5d c3 55 }
            // n = 7, score = 200
            //   eb06                 | jmp                 8
            //   d3ea                 | shr                 edx, cl
            //   89d0                 | mov                 eax, edx
            //   31d2                 | xor                 edx, edx
            //   5d                   | pop                 ebp
            //   c3                   | ret                 
            //   55                   | push                ebp

        $sequence_5 = { c3 8b44240c 8364242c00 c74424281c000000 8364242400 8364242000 8d742410 }
            // n = 7, score = 200
            //   c3                   | ret                 
            //   8b44240c             | mov                 eax, dword ptr [esp + 0xc]
            //   8364242c00           | and                 dword ptr [esp + 0x2c], 0
            //   c74424281c000000     | mov                 dword ptr [esp + 0x28], 0x1c
            //   8364242400           | and                 dword ptr [esp + 0x24], 0
            //   8364242000           | and                 dword ptr [esp + 0x20], 0
            //   8d742410             | lea                 esi, [esp + 0x10]

        $sequence_6 = { e8???????? 59 5a 56 ffd0 eb19 89f1 }
            // n = 7, score = 200
            //   e8????????           |                     
            //   59                   | pop                 ecx
            //   5a                   | pop                 edx
            //   56                   | push                esi
            //   ffd0                 | call                eax
            //   eb19                 | jmp                 0x1b
            //   89f1                 | mov                 ecx, esi

        $sequence_7 = { e9???????? 8b5de4 ba???????? 31c9 b001 8955dc 89ca }
            // n = 7, score = 200
            //   e9????????           |                     
            //   8b5de4               | mov                 ebx, dword ptr [ebp - 0x1c]
            //   ba????????           |                     
            //   31c9                 | xor                 ecx, ecx
            //   b001                 | mov                 al, 1
            //   8955dc               | mov                 dword ptr [ebp - 0x24], edx
            //   89ca                 | mov                 edx, ecx

        $sequence_8 = { c1e70e 09cf 84c9 7816 c1e607 89da b106 }
            // n = 7, score = 200
            //   c1e70e               | shl                 edi, 0xe
            //   09cf                 | or                  edi, ecx
            //   84c9                 | test                cl, cl
            //   7816                 | js                  0x18
            //   c1e607               | shl                 esi, 7
            //   89da                 | mov                 edx, ebx
            //   b106                 | mov                 cl, 6

        $sequence_9 = { b320 c745e400000000 0fadfa d3ef 84d9 b900000000 89fb }
            // n = 7, score = 200
            //   b320                 | mov                 bl, 0x20
            //   c745e400000000       | mov                 dword ptr [ebp - 0x1c], 0
            //   0fadfa               | shrd                edx, edi, cl
            //   d3ef                 | shr                 edi, cl
            //   84d9                 | test                cl, bl
            //   b900000000           | mov                 ecx, 0
            //   89fb                 | mov                 ebx, edi

    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
}