rule win_wndtest_auto {

    meta:
        author = "Felix Bilstein - yara-signator at cocacoding dot com"
        date = "2026-09-17"
        version = "1"
        description = "Detects win.wndtest."
        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.wndtest"
        malpedia_rule_date = "20260916"
        malpedia_hash = "53a643781c18e08f4a50949af60172d837a0b6f6"
        malpedia_version = "20260917"
        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 = { e8???????? 83c408 50 56 ffd7 833d????????00 a3???????? }
            // n = 7, score = 400
            //   e8????????           |                     
            //   83c408               | add                 esp, 8
            //   50                   | push                eax
            //   56                   | push                esi
            //   ffd7                 | call                edi
            //   833d????????00       |                     
            //   a3????????           |                     

        $sequence_1 = { b8???????? 2bc7 53 8945fc eb03 8b45fc 8b5d08 }
            // n = 7, score = 400
            //   b8????????           |                     
            //   2bc7                 | sub                 eax, edi
            //   53                   | push                ebx
            //   8945fc               | mov                 dword ptr [ebp - 4], eax
            //   eb03                 | jmp                 5
            //   8b45fc               | mov                 eax, dword ptr [ebp - 4]
            //   8b5d08               | mov                 ebx, dword ptr [ebp + 8]

        $sequence_2 = { 8d55e0 52 ffd3 6a00 6a00 6a00 8d45e0 }
            // n = 7, score = 400
            //   8d55e0               | lea                 edx, [ebp - 0x20]
            //   52                   | push                edx
            //   ffd3                 | call                ebx
            //   6a00                 | push                0
            //   6a00                 | push                0
            //   6a00                 | push                0
            //   8d45e0               | lea                 eax, [ebp - 0x20]

        $sequence_3 = { 7413 6a00 e8???????? 83c404 b001 5f 5e }
            // n = 7, score = 400
            //   7413                 | je                  0x15
            //   6a00                 | push                0
            //   e8????????           |                     
            //   83c404               | add                 esp, 4
            //   b001                 | mov                 al, 1
            //   5f                   | pop                 edi
            //   5e                   | pop                 esi

        $sequence_4 = { 50 e8???????? 83c408 50 56 ffd7 833d????????00 }
            // n = 7, score = 400
            //   50                   | push                eax
            //   e8????????           |                     
            //   83c408               | add                 esp, 8
            //   50                   | push                eax
            //   56                   | push                esi
            //   ffd7                 | call                edi
            //   833d????????00       |                     

        $sequence_5 = { d3e6 0bc6 d1eb 49 4a 75ec }
            // n = 6, score = 400
            //   d3e6                 | shl                 esi, cl
            //   0bc6                 | or                  eax, esi
            //   d1eb                 | shr                 ebx, 1
            //   49                   | dec                 ecx
            //   4a                   | dec                 edx
            //   75ec                 | jne                 0xffffffee

        $sequence_6 = { a3???????? a1???????? 50 51 e8???????? 83c408 50 }
            // n = 7, score = 400
            //   a3????????           |                     
            //   a1????????           |                     
            //   50                   | push                eax
            //   51                   | push                ecx
            //   e8????????           |                     
            //   83c408               | add                 esp, 8
            //   50                   | push                eax

        $sequence_7 = { ffd7 8b15???????? a3???????? a1???????? 52 50 e8???????? }
            // n = 7, score = 400
            //   ffd7                 | call                edi
            //   8b15????????         |                     
            //   a3????????           |                     
            //   a1????????           |                     
            //   52                   | push                edx
            //   50                   | push                eax
            //   e8????????           |                     

        $sequence_8 = { 8be5 5d c3 6a00 ff15???????? eb10 }
            // n = 6, score = 400
            //   8be5                 | mov                 esp, ebp
            //   5d                   | pop                 ebp
            //   c3                   | ret                 
            //   6a00                 | push                0
            //   ff15????????         |                     
            //   eb10                 | jmp                 0x12

        $sequence_9 = { ffd7 8d55e0 52 ffd3 6a00 }
            // n = 5, score = 400
            //   ffd7                 | call                edi
            //   8d55e0               | lea                 edx, [ebp - 0x20]
            //   52                   | push                edx
            //   ffd3                 | call                ebx
            //   6a00                 | push                0

    condition:
        7 of them and filesize < 901120
}

rule win_wndtest_w0 {
	meta:
		description = "Backdoor used by attackers in Operation Cleaver"
		reference = "http://cylance.com/assets/Cleaver/Cylance_Operation_Cleaver_Report.pdf"
		date = "2014/12/02"
		author = "Cylance Inc."
        malpedia_reference = "https://malpedia.caad.fkie.fraunhofer.de/details/win.wndtest"
        malpedia_version = "20170521"
        malpedia_license = "CC BY-NC-SA 4.0"
        malpedia_sharing = "TLP:WHITE"
	strings:
		$s1 = "[Alt]" wide
		$s2 = "<< %s >>:" wide
		$s3 = "Content-Disposition: inline; comp=%s; account=%s; product=%d;"
	condition:
		all of them
}