rule win_furtim_auto {

    meta:
        author = "Felix Bilstein - yara-signator at cocacoding dot com"
        date = "2026-05-04"
        version = "1"
        description = "Detects win.furtim."
        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.furtim"
        malpedia_rule_date = "20260422"
        malpedia_hash = "a182e35da64e6d71cb55f125c4d4225196523f14"
        malpedia_version = "20260504"
        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 = { 5b 5e 83c578 c9 c3 8bff 56 }
            // n = 7, score = 100
            //   5b                   | pop                 ebx
            //   5e                   | pop                 esi
            //   83c578               | add                 ebp, 0x78
            //   c9                   | leave               
            //   c3                   | ret                 
            //   8bff                 | mov                 edi, edi
            //   56                   | push                esi

        $sequence_1 = { 8bce 84c0 74e7 bf???????? eb0d 6a64 5a }
            // n = 7, score = 100
            //   8bce                 | mov                 ecx, esi
            //   84c0                 | test                al, al
            //   74e7                 | je                  0xffffffe9
            //   bf????????           |                     
            //   eb0d                 | jmp                 0xf
            //   6a64                 | push                0x64
            //   5a                   | pop                 edx

        $sequence_2 = { 52 8d45f4 8bf1 50 ff963c050000 8b4508 }
            // n = 6, score = 100
            //   52                   | push                edx
            //   8d45f4               | lea                 eax, [ebp - 0xc]
            //   8bf1                 | mov                 esi, ecx
            //   50                   | push                eax
            //   ff963c050000         | call                dword ptr [esi + 0x53c]
            //   8b4508               | mov                 eax, dword ptr [ebp + 8]

        $sequence_3 = { 895dfc ff960c030000 85c0 740f }
            // n = 4, score = 100
            //   895dfc               | mov                 dword ptr [ebp - 4], ebx
            //   ff960c030000         | call                dword ptr [esi + 0x30c]
            //   85c0                 | test                eax, eax
            //   740f                 | je                  0x11

        $sequence_4 = { 5b c3 56 8bf1 57 b9feff0000 ff96b8020000 }
            // n = 7, score = 100
            //   5b                   | pop                 ebx
            //   c3                   | ret                 
            //   56                   | push                esi
            //   8bf1                 | mov                 esi, ecx
            //   57                   | push                edi
            //   b9feff0000           | mov                 ecx, 0xfffe
            //   ff96b8020000         | call                dword ptr [esi + 0x2b8]

        $sequence_5 = { 57 c786500600006ec74000 c7862404000020db4000 c7869c03000068434000 c78698030000aa314000 c7863806000088c54000 c786c80500000c8d4000 }
            // n = 7, score = 100
            //   57                   | push                edi
            //   c786500600006ec74000     | mov    dword ptr [esi + 0x650], 0x40c76e
            //   c7862404000020db4000     | mov    dword ptr [esi + 0x424], 0x40db20
            //   c7869c03000068434000     | mov    dword ptr [esi + 0x39c], 0x404368
            //   c78698030000aa314000     | mov    dword ptr [esi + 0x398], 0x4031aa
            //   c7863806000088c54000     | mov    dword ptr [esi + 0x638], 0x40c588
            //   c786c80500000c8d4000     | mov    dword ptr [esi + 0x5c8], 0x408d0c

        $sequence_6 = { ba???????? 8bce ff9664060000 68???????? ff9688050000 8bf8 }
            // n = 6, score = 100
            //   ba????????           |                     
            //   8bce                 | mov                 ecx, esi
            //   ff9664060000         | call                dword ptr [esi + 0x664]
            //   68????????           |                     
            //   ff9688050000         | call                dword ptr [esi + 0x588]
            //   8bf8                 | mov                 edi, eax

        $sequence_7 = { 817dfce8030000 0f8f8c000000 8b5df8 83c310 68???????? 53 ff96c8040000 }
            // n = 7, score = 100
            //   817dfce8030000       | cmp                 dword ptr [ebp - 4], 0x3e8
            //   0f8f8c000000         | jg                  0x92
            //   8b5df8               | mov                 ebx, dword ptr [ebp - 8]
            //   83c310               | add                 ebx, 0x10
            //   68????????           |                     
            //   53                   | push                ebx
            //   ff96c8040000         | call                dword ptr [esi + 0x4c8]

        $sequence_8 = { ffd0 85c0 7467 397df8 7462 ff75fc ff96bc040000 }
            // n = 7, score = 100
            //   ffd0                 | call                eax
            //   85c0                 | test                eax, eax
            //   7467                 | je                  0x69
            //   397df8               | cmp                 dword ptr [ebp - 8], edi
            //   7462                 | je                  0x64
            //   ff75fc               | push                dword ptr [ebp - 4]
            //   ff96bc040000         | call                dword ptr [esi + 0x4bc]

        $sequence_9 = { 83e6f8 33c9 8b3c8a 83e7f8 3bfe 740b 41 }
            // n = 7, score = 100
            //   83e6f8               | and                 esi, 0xfffffff8
            //   33c9                 | xor                 ecx, ecx
            //   8b3c8a               | mov                 edi, dword ptr [edx + ecx*4]
            //   83e7f8               | and                 edi, 0xfffffff8
            //   3bfe                 | cmp                 edi, esi
            //   740b                 | je                  0xd
            //   41                   | inc                 ecx

    condition:
        7 of them and filesize < 622592
}