rule win_nachocheese_auto {

    meta:
        author = "Felix Bilstein - yara-signator at cocacoding dot com"
        date = "2023-07-11"
        version = "1"
        description = "Detects win.nachocheese."
        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.nachocheese"
        malpedia_rule_date = "20230705"
        malpedia_hash = "42d0574f4405bd7d2b154d321d345acb18834a41"
        malpedia_version = "20230715"
        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 = { 8d95e4fdffff 52 8d0c00 56 }
            // n = 4, score = 300
            //   8d95e4fdffff         | lea                 edx, [ebp - 0x21c]
            //   52                   | push                edx
            //   8d0c00               | lea                 ecx, [eax + eax]
            //   56                   | push                esi

        $sequence_1 = { 2d???????? 50 68???????? 8d8df8feffff 6804010000 }
            // n = 5, score = 300
            //   2d????????           |                     
            //   50                   | push                eax
            //   68????????           |                     
            //   8d8df8feffff         | lea                 ecx, [ebp - 0x108]
            //   6804010000           | push                0x104

        $sequence_2 = { 2bfa 8d47fd 3901 8901 }
            // n = 4, score = 300
            //   2bfa                 | sub                 edi, edx
            //   8d47fd               | lea                 eax, [edi - 3]
            //   3901                 | cmp                 dword ptr [ecx], eax
            //   8901                 | mov                 dword ptr [ecx], eax

        $sequence_3 = { 3d9f000000 7e0d 33c0 c3 05d13fffff 83f801 77f3 }
            // n = 7, score = 300
            //   3d9f000000           | cmp                 eax, 0x9f
            //   7e0d                 | jle                 0xf
            //   33c0                 | xor                 eax, eax
            //   c3                   | ret                 
            //   05d13fffff           | add                 eax, 0xffff3fd1
            //   83f801               | cmp                 eax, 1
            //   77f3                 | ja                  0xfffffff5

        $sequence_4 = { 52 ff15???????? 83f801 754b 8b450c 8b4dfc 6a00 }
            // n = 7, score = 300
            //   52                   | push                edx
            //   ff15????????         |                     
            //   83f801               | cmp                 eax, 1
            //   754b                 | jne                 0x4d
            //   8b450c               | mov                 eax, dword ptr [ebp + 0xc]
            //   8b4dfc               | mov                 ecx, dword ptr [ebp - 4]
            //   6a00                 | push                0

        $sequence_5 = { 3d2cc00000 7f18 3d2bc00000 7d1b 3d9c000000 7c07 3d9f000000 }
            // n = 7, score = 300
            //   3d2cc00000           | cmp                 eax, 0xc02c
            //   7f18                 | jg                  0x1a
            //   3d2bc00000           | cmp                 eax, 0xc02b
            //   7d1b                 | jge                 0x1d
            //   3d9c000000           | cmp                 eax, 0x9c
            //   7c07                 | jl                  9
            //   3d9f000000           | cmp                 eax, 0x9f

        $sequence_6 = { 57 8b7df4 3bfb 0f847f000000 90 8b4704 83f802 }
            // n = 7, score = 300
            //   57                   | push                edi
            //   8b7df4               | mov                 edi, dword ptr [ebp - 0xc]
            //   3bfb                 | cmp                 edi, ebx
            //   0f847f000000         | je                  0x85
            //   90                   | nop                 
            //   8b4704               | mov                 eax, dword ptr [edi + 4]
            //   83f802               | cmp                 eax, 2

        $sequence_7 = { 33c0 8945fc eb58 8b0d???????? 8d4604 50 6a00 }
            // n = 7, score = 300
            //   33c0                 | xor                 eax, eax
            //   8945fc               | mov                 dword ptr [ebp - 4], eax
            //   eb58                 | jmp                 0x5a
            //   8b0d????????         |                     
            //   8d4604               | lea                 eax, [esi + 4]
            //   50                   | push                eax
            //   6a00                 | push                0

        $sequence_8 = { 68???????? 8d8de4faffff 6804010000 51 0fb7f0 e8???????? b8???????? }
            // n = 7, score = 300
            //   68????????           |                     
            //   8d8de4faffff         | lea                 ecx, [ebp - 0x51c]
            //   6804010000           | push                0x104
            //   51                   | push                ecx
            //   0fb7f0               | movzx               esi, ax
            //   e8????????           |                     
            //   b8????????           |                     

        $sequence_9 = { 81fb80000000 7305 83c302 eb29 }
            // n = 4, score = 300
            //   81fb80000000         | cmp                 ebx, 0x80
            //   7305                 | jae                 7
            //   83c302               | add                 ebx, 2
            //   eb29                 | jmp                 0x2b

        $sequence_10 = { 7305 83c303 eb1c 81fb00000100 }
            // n = 4, score = 300
            //   7305                 | jae                 7
            //   83c303               | add                 ebx, 3
            //   eb1c                 | jmp                 0x1e
            //   81fb00000100         | cmp                 ebx, 0x10000

        $sequence_11 = { 02ca 8b55fc 880c3e 8a540205 32d1 }
            // n = 5, score = 300
            //   02ca                 | add                 cl, dl
            //   8b55fc               | mov                 edx, dword ptr [ebp - 4]
            //   880c3e               | mov                 byte ptr [esi + edi], cl
            //   8a540205             | mov                 dl, byte ptr [edx + eax + 5]
            //   32d1                 | xor                 dl, cl

        $sequence_12 = { ba???????? 2bd0 83c2fe 8d4813 894dec }
            // n = 5, score = 300
            //   ba????????           |                     
            //   2bd0                 | sub                 edx, eax
            //   83c2fe               | add                 edx, -2
            //   8d4813               | lea                 ecx, [eax + 0x13]
            //   894dec               | mov                 dword ptr [ebp - 0x14], ecx

        $sequence_13 = { 33c8 894710 8b4708 33c1 }
            // n = 4, score = 300
            //   33c8                 | xor                 ecx, eax
            //   894710               | mov                 dword ptr [edi + 0x10], eax
            //   8b4708               | mov                 eax, dword ptr [edi + 8]
            //   33c1                 | xor                 eax, ecx

        $sequence_14 = { 7305 83c304 eb0f 81fb00000001 }
            // n = 4, score = 300
            //   7305                 | jae                 7
            //   83c304               | add                 ebx, 4
            //   eb0f                 | jmp                 0x11
            //   81fb00000001         | cmp                 ebx, 0x1000000

        $sequence_15 = { 763a b801011000 f7e6 8bc6 }
            // n = 4, score = 300
            //   763a                 | jbe                 0x3c
            //   b801011000           | mov                 eax, 0x100101
            //   f7e6                 | mul                 esi
            //   8bc6                 | mov                 eax, esi

    condition:
        7 of them and filesize < 1064960
}