rule win_koobface_auto {

    meta:
        author = "Felix Bilstein - yara-signator at cocacoding dot com"
        date = "2026-05-04"
        version = "1"
        description = "Detects win.koobface."
        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.koobface"
        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 = { 03048da0534200 eb02 8bc2 f6402480 0f8571ffffff 33f6 }
            // n = 6, score = 100
            //   03048da0534200       | add                 eax, dword ptr [ecx*4 + 0x4253a0]
            //   eb02                 | jmp                 4
            //   8bc2                 | mov                 eax, edx
            //   f6402480             | test                byte ptr [eax + 0x24], 0x80
            //   0f8571ffffff         | jne                 0xffffff77
            //   33f6                 | xor                 esi, esi

        $sequence_1 = { 50 c645fc1e e8???????? 56 8945b4 e8???????? 59 }
            // n = 7, score = 100
            //   50                   | push                eax
            //   c645fc1e             | mov                 byte ptr [ebp - 4], 0x1e
            //   e8????????           |                     
            //   56                   | push                esi
            //   8945b4               | mov                 dword ptr [ebp - 0x4c], eax
            //   e8????????           |                     
            //   59                   | pop                 ecx

        $sequence_2 = { 754c 8d8540c1ffff 6a41 50 e8???????? 59 }
            // n = 6, score = 100
            //   754c                 | jne                 0x4e
            //   8d8540c1ffff         | lea                 eax, [ebp - 0x3ec0]
            //   6a41                 | push                0x41
            //   50                   | push                eax
            //   e8????????           |                     
            //   59                   | pop                 ecx

        $sequence_3 = { 6a02 8985d4c1ffff ff15???????? 8bd8 83ceff 899d84bfffff 3bde }
            // n = 7, score = 100
            //   6a02                 | push                2
            //   8985d4c1ffff         | mov                 dword ptr [ebp - 0x3e2c], eax
            //   ff15????????         |                     
            //   8bd8                 | mov                 ebx, eax
            //   83ceff               | or                  esi, 0xffffffff
            //   899d84bfffff         | mov                 dword ptr [ebp - 0x407c], ebx
            //   3bde                 | cmp                 ebx, esi

        $sequence_4 = { 55 8bec 8b450c 832000 33c0 40 5d }
            // n = 7, score = 100
            //   55                   | push                ebp
            //   8bec                 | mov                 ebp, esp
            //   8b450c               | mov                 eax, dword ptr [ebp + 0xc]
            //   832000               | and                 dword ptr [eax], 0
            //   33c0                 | xor                 eax, eax
            //   40                   | inc                 eax
            //   5d                   | pop                 ebp

        $sequence_5 = { 8d3402 56 e8???????? 56 8d45b4 50 8d4d94 }
            // n = 7, score = 100
            //   8d3402               | lea                 esi, [edx + eax]
            //   56                   | push                esi
            //   e8????????           |                     
            //   56                   | push                esi
            //   8d45b4               | lea                 eax, [ebp - 0x4c]
            //   50                   | push                eax
            //   8d4d94               | lea                 ecx, [ebp - 0x6c]

        $sequence_6 = { 8d8528ffffff 68???????? 50 e8???????? 83c40c 8d8528ffffff 50 }
            // n = 7, score = 100
            //   8d8528ffffff         | lea                 eax, [ebp - 0xd8]
            //   68????????           |                     
            //   50                   | push                eax
            //   e8????????           |                     
            //   83c40c               | add                 esp, 0xc
            //   8d8528ffffff         | lea                 eax, [ebp - 0xd8]
            //   50                   | push                eax

        $sequence_7 = { e8???????? c3 55 8bec ff7510 ff750c e8???????? }
            // n = 7, score = 100
            //   e8????????           |                     
            //   c3                   | ret                 
            //   55                   | push                ebp
            //   8bec                 | mov                 ebp, esp
            //   ff7510               | push                dword ptr [ebp + 0x10]
            //   ff750c               | push                dword ptr [ebp + 0xc]
            //   e8????????           |                     

        $sequence_8 = { 3d???????? 72f1 5d c3 0fb611 }
            // n = 5, score = 100
            //   3d????????           |                     
            //   72f1                 | jb                  0xfffffff3
            //   5d                   | pop                 ebp
            //   c3                   | ret                 
            //   0fb611               | movzx               edx, byte ptr [ecx]

        $sequence_9 = { 57 c645fc04 ff5124 ff7508 }
            // n = 4, score = 100
            //   57                   | push                edi
            //   c645fc04             | mov                 byte ptr [ebp - 4], 4
            //   ff5124               | call                dword ptr [ecx + 0x24]
            //   ff7508               | push                dword ptr [ebp + 8]

    condition:
        7 of them and filesize < 368640
}