rule win_vidar_auto {

    meta:
        author = "Felix Bilstein - yara-signator at cocacoding dot com"
        date = "2020-10-14"
        version = "1"
        description = "autogenerated rule brought to you by yara-signator"
        tool = "yara-signator v0.5.0"
        tool_config = "callsandjumps;datarefs;binvalue"
        malpedia_reference = "https://malpedia.caad.fkie.fraunhofer.de/details/win.vidar"
        malpedia_rule_date = "20201014"
        malpedia_hash = "a7e3bd57eaf12bf3ea29a863c041091ba3af9ac9"
        malpedia_version = "20201014"
        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 = { 56 8b742408 8b06 8b4804 6a0a }
            // n = 5, score = 1000
            //   56                   | push                esi
            //   8b742408             | mov                 esi, dword ptr [esp + 8]
            //   8b06                 | mov                 eax, dword ptr [esi]
            //   8b4804               | mov                 ecx, dword ptr [eax + 4]
            //   6a0a                 | push                0xa

        $sequence_1 = { c3 56 8d71f8 8bce e8???????? f644240801 7407 }
            // n = 7, score = 1000
            //   c3                   | ret                 
            //   56                   | push                esi
            //   8d71f8               | lea                 esi, [ecx - 8]
            //   8bce                 | mov                 ecx, esi
            //   e8????????           |                     
            //   f644240801           | test                byte ptr [esp + 8], 1
            //   7407                 | je                  9

        $sequence_2 = { 8b4508 8906 8b450c 894608 }
            // n = 4, score = 1000
            //   8b4508               | mov                 eax, dword ptr [ebp + 8]
            //   8906                 | mov                 dword ptr [esi], eax
            //   8b450c               | mov                 eax, dword ptr [ebp + 0xc]
            //   894608               | mov                 dword ptr [esi + 8], eax

        $sequence_3 = { e8???????? 59 83f8ff 7503 32c0 c3 8b4c2404 }
            // n = 7, score = 1000
            //   e8????????           |                     
            //   59                   | pop                 ecx
            //   83f8ff               | cmp                 eax, -1
            //   7503                 | jne                 5
            //   32c0                 | xor                 al, al
            //   c3                   | ret                 
            //   8b4c2404             | mov                 ecx, dword ptr [esp + 4]

        $sequence_4 = { 5e c20400 b001 c3 33c0 }
            // n = 5, score = 1000
            //   5e                   | pop                 esi
            //   c20400               | ret                 4
            //   b001                 | mov                 al, 1
            //   c3                   | ret                 
            //   33c0                 | xor                 eax, eax

        $sequence_5 = { c9 c3 8b542408 85d2 7503 33c0 c3 }
            // n = 7, score = 1000
            //   c9                   | leave               
            //   c3                   | ret                 
            //   8b542408             | mov                 edx, dword ptr [esp + 8]
            //   85d2                 | test                edx, edx
            //   7503                 | jne                 5
            //   33c0                 | xor                 eax, eax
            //   c3                   | ret                 

        $sequence_6 = { e8???????? 0fb6c0 50 ff742410 56 e8???????? 83c40c }
            // n = 7, score = 1000
            //   e8????????           |                     
            //   0fb6c0               | movzx               eax, al
            //   50                   | push                eax
            //   ff742410             | push                dword ptr [esp + 0x10]
            //   56                   | push                esi
            //   e8????????           |                     
            //   83c40c               | add                 esp, 0xc

        $sequence_7 = { 5e c20800 56 57 8b7c240c 8b07 }
            // n = 6, score = 1000
            //   5e                   | pop                 esi
            //   c20800               | ret                 8
            //   56                   | push                esi
            //   57                   | push                edi
            //   8b7c240c             | mov                 edi, dword ptr [esp + 0xc]
            //   8b07                 | mov                 eax, dword ptr [edi]

        $sequence_8 = { c3 8bff 55 8bec 83ec0c c745fc00000000 }
            // n = 6, score = 200
            //   c3                   | ret                 
            //   8bff                 | mov                 edi, edi
            //   55                   | push                ebp
            //   8bec                 | mov                 ebp, esp
            //   83ec0c               | sub                 esp, 0xc
            //   c745fc00000000       | mov                 dword ptr [ebp - 4], 0

        $sequence_9 = { 6a0b 6a10 e8???????? 83c41c 8be5 }
            // n = 5, score = 200
            //   6a0b                 | push                0xb
            //   6a10                 | push                0x10
            //   e8????????           |                     
            //   83c41c               | add                 esp, 0x1c
            //   8be5                 | mov                 esp, ebp

        $sequence_10 = { dc05???????? 83ec08 dd1c24 83ec08 dd4508 dd1c24 6a0b }
            // n = 7, score = 200
            //   dc05????????         |                     
            //   83ec08               | sub                 esp, 8
            //   dd1c24               | fstp                qword ptr [esp]
            //   83ec08               | sub                 esp, 8
            //   dd4508               | fld                 qword ptr [ebp + 8]
            //   dd1c24               | fstp                qword ptr [esp]
            //   6a0b                 | push                0xb

        $sequence_11 = { 8d4e01 894c2424 83fd10 723d 8b742430 56 50 }
            // n = 7, score = 100
            //   8d4e01               | lea                 ecx, [esi + 1]
            //   894c2424             | mov                 dword ptr [esp + 0x24], ecx
            //   83fd10               | cmp                 ebp, 0x10
            //   723d                 | jb                  0x3f
            //   8b742430             | mov                 esi, dword ptr [esp + 0x30]
            //   56                   | push                esi
            //   50                   | push                eax

        $sequence_12 = { e8???????? 83c418 837d0802 757f 8b4d08 8b148d48e94800 }
            // n = 6, score = 100
            //   e8????????           |                     
            //   83c418               | add                 esp, 0x18
            //   837d0802             | cmp                 dword ptr [ebp + 8], 2
            //   757f                 | jne                 0x81
            //   8b4d08               | mov                 ecx, dword ptr [ebp + 8]
            //   8b148d48e94800       | mov                 edx, dword ptr [ecx*4 + 0x48e948]

        $sequence_13 = { e8???????? 83c404 8bd8 895dd0 8b4de4 8d04cd00000000 2bc1 }
            // n = 7, score = 100
            //   e8????????           |                     
            //   83c404               | add                 esp, 4
            //   8bd8                 | mov                 ebx, eax
            //   895dd0               | mov                 dword ptr [ebp - 0x30], ebx
            //   8b4de4               | mov                 ecx, dword ptr [ebp - 0x1c]
            //   8d04cd00000000       | lea                 eax, [ecx*8]
            //   2bc1                 | sub                 eax, ecx

    condition:
        7 of them and filesize < 2793472
}

rule win_vidar_w0 {
    meta:
        description = "Yara rule for detecting Vidar stealer"
        author = "Fumik0_"
        malpedia_reference = "https://malpedia.caad.fkie.fraunhofer.de/details/win.vidar"
        malpedia_version = "20190106"
        malpedia_license = "CC BY-NC-SA 4.0"
        malpedia_sharing = "TLP:WHITE"

    strings:
        $s1 = { 56 69 64 61 72 }
        $s2 = { 31 42 45 46 30 41 35 37 42 45 31 31 30 46 44 34 36 37 41 }
        
    condition:
        all of them
}