rule win_winnti_auto { meta: author = "Felix Bilstein - yara-signator at cocacoding dot com" date = "2026-09-17" version = "1" description = "Detects win.winnti." 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.winnti" 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 = { 81e6ffff0000 ff15???????? c1e010 0bf0 } // n = 4, score = 200 // 81e6ffff0000 | and esi, 0xffff // ff15???????? | // c1e010 | shl eax, 0x10 // 0bf0 | or esi, eax $sequence_1 = { 740c 8902 8b442410 03c1 89442410 } // n = 5, score = 200 // 740c | je 0xe // 8902 | mov dword ptr [edx], eax // 8b442410 | mov eax, dword ptr [esp + 0x10] // 03c1 | add eax, ecx // 89442410 | mov dword ptr [esp + 0x10], eax $sequence_2 = { 3bc7 897c2430 7409 8bc8 e8???????? eb02 } // n = 6, score = 200 // 3bc7 | cmp eax, edi // 897c2430 | mov dword ptr [esp + 0x30], edi // 7409 | je 0xb // 8bc8 | mov ecx, eax // e8???????? | // eb02 | jmp 4 $sequence_3 = { 83e103 f3a4 8b7c2470 83c9ff } // n = 4, score = 200 // 83e103 | and ecx, 3 // f3a4 | rep movsb byte ptr es:[edi], byte ptr [esi] // 8b7c2470 | mov edi, dword ptr [esp + 0x70] // 83c9ff | or ecx, 0xffffffff $sequence_4 = { 8d7c1901 e8???????? 6a04 53 8d442418 } // n = 5, score = 200 // 8d7c1901 | lea edi, [ecx + ebx + 1] // e8???????? | // 6a04 | push 4 // 53 | push ebx // 8d442418 | lea eax, [esp + 0x18] $sequence_5 = { 896c2418 55 e8???????? 8bd0 } // n = 4, score = 200 // 896c2418 | mov dword ptr [esp + 0x18], ebp // 55 | push ebp // e8???????? | // 8bd0 | mov edx, eax $sequence_6 = { 55 56 8b4330 8b4b2c 8b35???????? } // n = 5, score = 200 // 55 | push ebp // 56 | push esi // 8b4330 | mov eax, dword ptr [ebx + 0x30] // 8b4b2c | mov ecx, dword ptr [ebx + 0x2c] // 8b35???????? | $sequence_7 = { 50 56 e8???????? 83c408 eb9b 8b561c 52 } // n = 7, score = 200 // 50 | push eax // 56 | push esi // e8???????? | // 83c408 | add esp, 8 // eb9b | jmp 0xffffff9d // 8b561c | mov edx, dword ptr [esi + 0x1c] // 52 | push edx $sequence_8 = { 458d60f8 4488443039 4180fd01 752e 4b8b84f900a20b00 8a4c303a 413ac8 } // n = 7, score = 100 // 458d60f8 | inc ebp // 4488443039 | lea esp, [eax - 8] // 4180fd01 | inc esp // 752e | mov byte ptr [eax + esi + 0x39], al // 4b8b84f900a20b00 | inc ecx // 8a4c303a | cmp ch, 1 // 413ac8 | jne 0x30 $sequence_9 = { 4055 4883ec60 488bea 488b8d00010000 4885c9 741e } // n = 6, score = 100 // 4055 | inc ecx // 4883ec60 | or eax, eax // 488bea | dec eax // 488b8d00010000 | lea edx, [esp + 0x58] // 4885c9 | dec eax // 741e | lea ecx, [0xb21b3] $sequence_10 = { 488b8c24b0000000 ff15???????? 8bd8 85c0 7848 488b8c24b0000000 } // n = 6, score = 100 // 488b8c24b0000000 | lea ecx, [0xffff0f05] // ff15???????? | // 8bd8 | inc ebp // 85c0 | mov ah, byte ptr [eax] // 7848 | inc ebp // 488b8c24b0000000 | test ah, ah $sequence_11 = { 7539 410bc0 488d542458 488d0db3210b00 8905???????? 488d05a61e0100 } // n = 6, score = 100 // 7539 | dec eax // 410bc0 | lea eax, [0xa975d] // 488d542458 | dec eax // 488d0db3210b00 | add edi, 8 // 8905???????? | // 488d05a61e0100 | dec eax $sequence_12 = { 448be0 85c0 0f844e010000 488b4c2450 488364242000 488d055d970a00 } // n = 6, score = 100 // 448be0 | dec eax // 85c0 | arpl cx, bx // 0f844e010000 | dec eax // 488b4c2450 | lea ebp, [0xa507f] // 488364242000 | dec eax // 488d055d970a00 | mov edi, ebx $sequence_13 = { e8???????? 4883c708 4883ff38 7cc2 488b0e } // n = 5, score = 100 // e8???????? | // 4883c708 | and ebx, 0x1f // 4883ff38 | dec eax // 7cc2 | sar edi, 5 // 488b0e | inc esp $sequence_14 = { 488bcf e8???????? 85c0 7442 488d15726b0000 } // n = 5, score = 100 // 488bcf | cmp edi, 0x38 // e8???????? | // 85c0 | jl 0xffffffe4 // 7442 | dec eax // 488d15726b0000 | mov ecx, dword ptr [esi] $sequence_15 = { 7404 66458918 33c0 e9???????? 458bd3 44895c2404 } // n = 6, score = 100 // 7404 | dec eax // 66458918 | lea edx, [0x155cb] // 33c0 | dec eax // e9???????? | // 458bd3 | mov ecx, ebx // 44895c2404 | jne 0x4f $sequence_16 = { 0fb74c3c40 8d41bf 6683f819 7704 6683c120 } // n = 5, score = 100 // 0fb74c3c40 | dec eax // 8d41bf | lea eax, [0x11ea6] // 6683f819 | dec eax // 7704 | mov ecx, edi // 6683c120 | test eax, eax $sequence_17 = { 42813c39eb06881d 740b ffc0 8bc8 483bca 72ed eb2d } // n = 7, score = 100 // 42813c39eb06881d | inc ebp // 740b | dec eax // ffc0 | lea edx, [0xf27c] // 8bc8 | dec eax // 483bca | mov ecx, ebp // 72ed | dec esp // eb2d | mov eax, dword ptr [esp + 0x68] $sequence_18 = { 4889442420 41b901000000 4533c0 488d542440 } // n = 4, score = 100 // 4889442420 | je 0x46 // 41b901000000 | dec eax // 4533c0 | lea edx, [0x6b72] // 488d542440 | dec eax $sequence_19 = { 7e22 48897b18 48897310 408833 4533c0 488d15cb550100 488bcb } // n = 7, score = 100 // 7e22 | mov esp, eax // 48897b18 | test eax, eax // 48897310 | je 0x154 // 408833 | dec eax // 4533c0 | mov ecx, dword ptr [esp + 0x50] // 488d15cb550100 | dec eax // 488bcb | and dword ptr [esp + 0x20], 0 $sequence_20 = { c7459f30000000 c745a338000000 48c745a742000042 895dbf } // n = 4, score = 100 // c7459f30000000 | mov edx, dword ptr [esp + 0x60] // c745a338000000 | inc ecx // 48c745a742000042 | mov ebx, 0x200 // 895dbf | dec esp $sequence_21 = { 85c0 0f8457010000 488bcf ff15???????? } // n = 4, score = 100 // 85c0 | je 6 // 0f8457010000 | inc bp // 488bcf | mov dword ptr [eax], ebx // ff15???????? | $sequence_22 = { 48ffc5 488d157cf20000 488bcd e8???????? } // n = 4, score = 100 // 48ffc5 | jle 0x24 // 488d157cf20000 | dec eax // 488bcd | mov dword ptr [ebx + 0x18], edi // e8???????? | $sequence_23 = { 3b0d???????? 7369 4863d9 488d2d7f500a00 488bfb 83e31f 48c1ff05 } // n = 7, score = 100 // 3b0d???????? | // 7369 | dec ebx // 4863d9 | mov eax, dword ptr [ecx + edi*8 + 0xba200] // 488d2d7f500a00 | mov cl, byte ptr [eax + esi + 0x3a] // 488bfb | inc ecx // 83e31f | cmp cl, al // 48c1ff05 | jae 0x6b condition: 7 of them and filesize < 1581056 }