rule win_vidar_auto {

    meta:
        author = "Felix Bilstein - yara-signator at cocacoding dot com"
        date = "2020-05-30"
        version = "1"
        description = "autogenerated rule brought to you by yara-signator"
        tool = "yara-signator v0.4.0"
        tool_config = "callsandjumps;datarefs;binvalue"
        malpedia_reference = "https://malpedia.caad.fkie.fraunhofer.de/details/win.vidar"
        malpedia_rule_date = "20200529"
        malpedia_hash = "92c362319514e5a6da26204961446caa3a8b32a8"
        malpedia_version = "20200529"
        malpedia_license = "CC BY-NC-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 / approach 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 = { c9 c3 8b542408 85d2 7503 }
            // n = 5, score = 1700
            //   c9                   | leave               
            //   c3                   | ret                 
            //   8b542408             | mov                 edx, dword ptr [esp + 8]
            //   85d2                 | test                edx, edx
            //   7503                 | jne                 5

        $sequence_1 = { 8b4120 8910 8b4130 8910 c3 56 }
            // n = 6, score = 1700
            //   8b4120               | mov                 eax, dword ptr [ecx + 0x20]
            //   8910                 | mov                 dword ptr [eax], edx
            //   8b4130               | mov                 eax, dword ptr [ecx + 0x30]
            //   8910                 | mov                 dword ptr [eax], edx
            //   c3                   | ret                 
            //   56                   | push                esi

        $sequence_2 = { c20400 ff742408 e8???????? 59 83f8ff 7503 }
            // n = 6, score = 1700
            //   c20400               | ret                 4
            //   ff742408             | push                dword ptr [esp + 8]
            //   e8????????           |                     
            //   59                   | pop                 ecx
            //   83f8ff               | cmp                 eax, -1
            //   7503                 | jne                 5

        $sequence_3 = { 8b4508 8906 8b450c 894608 8b4510 }
            // n = 5, score = 1700
            //   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
            //   8b4510               | mov                 eax, dword ptr [ebp + 0x10]

        $sequence_4 = { c20400 56 8bf1 8b4e20 33c0 }
            // n = 5, score = 1700
            //   c20400               | ret                 4
            //   56                   | push                esi
            //   8bf1                 | mov                 esi, ecx
            //   8b4e20               | mov                 ecx, dword ptr [esi + 0x20]
            //   33c0                 | xor                 eax, eax

        $sequence_5 = { c20800 56 57 8b7c240c 8b07 8bf1 8bcf }
            // n = 7, score = 1700
            //   c20800               | ret                 8
            //   56                   | push                esi
            //   57                   | push                edi
            //   8b7c240c             | mov                 edi, dword ptr [esp + 0xc]
            //   8b07                 | mov                 eax, dword ptr [edi]
            //   8bf1                 | mov                 esi, ecx
            //   8bcf                 | mov                 ecx, edi

        $sequence_6 = { e8???????? 0fb6c0 50 ff742410 56 e8???????? }
            // n = 6, score = 1700
            //   e8????????           |                     
            //   0fb6c0               | movzx               eax, al
            //   50                   | push                eax
            //   ff742410             | push                dword ptr [esp + 0x10]
            //   56                   | push                esi
            //   e8????????           |                     

        $sequence_7 = { 56 8b742408 8b06 8b4804 6a0a 03ce e8???????? }
            // n = 7, score = 1700
            //   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
            //   03ce                 | add                 ecx, esi
            //   e8????????           |                     

        $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 = { e8???????? ff35???????? a3???????? ff15???????? }
            // n = 4, score = 200
            //   e8????????           |                     
            //   ff35????????         |                     
            //   a3????????           |                     
            //   ff15????????         |                     

        $sequence_10 = { 83ec08 dd4508 dd1c24 6a0b 6a10 }
            // n = 5, score = 200
            //   83ec08               | sub                 esp, 8
            //   dd4508               | fld                 qword ptr [ebp + 8]
            //   dd1c24               | fstp                qword ptr [esp]
            //   6a0b                 | push                0xb
            //   6a10                 | push                0x10

        $sequence_11 = { 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_12 = { 83e03f 6bc038 8b149518154900 884c0228 eb1c }
            // n = 5, score = 100
            //   83e03f               | and                 eax, 0x3f
            //   6bc038               | imul                eax, eax, 0x38
            //   8b149518154900       | mov                 edx, dword ptr [edx*4 + 0x491518]
            //   884c0228             | mov                 byte ptr [edx + eax + 0x28], cl
            //   eb1c                 | jmp                 0x1e

        $sequence_13 = { ff9508bfffff 83c410 8945f4 8b55b8 0355f4 c60200 8b45e0 }
            // n = 7, score = 100
            //   ff9508bfffff         | call                dword ptr [ebp - 0x40f8]
            //   83c410               | add                 esp, 0x10
            //   8945f4               | mov                 dword ptr [ebp - 0xc], eax
            //   8b55b8               | mov                 edx, dword ptr [ebp - 0x48]
            //   0355f4               | add                 edx, dword ptr [ebp - 0xc]
            //   c60200               | mov                 byte ptr [edx], 0
            //   8b45e0               | mov                 eax, dword ptr [ebp - 0x20]

        $sequence_14 = { 50 e8???????? 8d44244c 50 8b442454 8d4c2474 }
            // n = 6, score = 100
            //   50                   | push                eax
            //   e8????????           |                     
            //   8d44244c             | lea                 eax, [esp + 0x4c]
            //   50                   | push                eax
            //   8b442454             | mov                 eax, dword ptr [esp + 0x54]
            //   8d4c2474             | lea                 ecx, [esp + 0x74]

    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
}