rule win_spora_ransom_auto {

    meta:
        author = "Felix Bilstein - yara-signator at cocacoding dot com"
        date = "2023-07-11"
        version = "1"
        description = "Detects win.spora_ransom."
        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.spora_ransom"
        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 = { 668945f0 58 ff7510 668945f2 ff750c }
            // n = 5, score = 200
            //   668945f0             | mov                 word ptr [ebp - 0x10], ax
            //   58                   | pop                 eax
            //   ff7510               | push                dword ptr [ebp + 0x10]
            //   668945f2             | mov                 word ptr [ebp - 0xe], ax
            //   ff750c               | push                dword ptr [ebp + 0xc]

        $sequence_1 = { 50 ff36 ff15???????? 85c0 7402 8b18 }
            // n = 6, score = 200
            //   50                   | push                eax
            //   ff36                 | push                dword ptr [esi]
            //   ff15????????         |                     
            //   85c0                 | test                eax, eax
            //   7402                 | je                  4
            //   8b18                 | mov                 ebx, dword ptr [eax]

        $sequence_2 = { 8d45e0 50 ff15???????? 0fb745e0 50 0fb745e2 50 }
            // n = 7, score = 200
            //   8d45e0               | lea                 eax, [ebp - 0x20]
            //   50                   | push                eax
            //   ff15????????         |                     
            //   0fb745e0             | movzx               eax, word ptr [ebp - 0x20]
            //   50                   | push                eax
            //   0fb745e2             | movzx               eax, word ptr [ebp - 0x1e]
            //   50                   | push                eax

        $sequence_3 = { 33c0 668945f4 8d45f0 50 ff15???????? }
            // n = 5, score = 200
            //   33c0                 | xor                 eax, eax
            //   668945f4             | mov                 word ptr [ebp - 0xc], ax
            //   8d45f0               | lea                 eax, [ebp - 0x10]
            //   50                   | push                eax
            //   ff15????????         |                     

        $sequence_4 = { 57 ff15???????? 57 e8???????? 57 ff15???????? 83c620 }
            // n = 7, score = 200
            //   57                   | push                edi
            //   ff15????????         |                     
            //   57                   | push                edi
            //   e8????????           |                     
            //   57                   | push                edi
            //   ff15????????         |                     
            //   83c620               | add                 esi, 0x20

        $sequence_5 = { ff36 ff15???????? 8d440010 50 }
            // n = 4, score = 200
            //   ff36                 | push                dword ptr [esi]
            //   ff15????????         |                     
            //   8d440010             | lea                 eax, [eax + eax + 0x10]
            //   50                   | push                eax

        $sequence_6 = { 50 e8???????? eb33 837ef001 752d ff36 ff15???????? }
            // n = 7, score = 200
            //   50                   | push                eax
            //   e8????????           |                     
            //   eb33                 | jmp                 0x35
            //   837ef001             | cmp                 dword ptr [esi - 0x10], 1
            //   752d                 | jne                 0x2f
            //   ff36                 | push                dword ptr [esi]
            //   ff15????????         |                     

        $sequence_7 = { ff15???????? 8bf8 3bfe 7438 57 53 }
            // n = 6, score = 200
            //   ff15????????         |                     
            //   8bf8                 | mov                 edi, eax
            //   3bfe                 | cmp                 edi, esi
            //   7438                 | je                  0x3a
            //   57                   | push                edi
            //   53                   | push                ebx

        $sequence_8 = { ff15???????? 57 6a40 ffd6 8b3d???????? 33f6 }
            // n = 6, score = 200
            //   ff15????????         |                     
            //   57                   | push                edi
            //   6a40                 | push                0x40
            //   ffd6                 | call                esi
            //   8b3d????????         |                     
            //   33f6                 | xor                 esi, esi

        $sequence_9 = { 8bf8 85ff 7416 ff36 57 }
            // n = 5, score = 200
            //   8bf8                 | mov                 edi, eax
            //   85ff                 | test                edi, edi
            //   7416                 | je                  0x18
            //   ff36                 | push                dword ptr [esi]
            //   57                   | push                edi

    condition:
        7 of them and filesize < 73728
}