rule win_winnti_auto { meta: author = "Felix Bilstein - yara-signator at cocacoding dot com" date = "2026-05-04" 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 = "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 = { 8d7c2410 33db f3ab 8d44240c } // n = 4, score = 200 // 8d7c2410 | lea edi, [esp + 0x10] // 33db | xor ebx, ebx // f3ab | rep stosd dword ptr es:[edi], eax // 8d44240c | lea eax, [esp + 0xc] $sequence_1 = { 8d442418 8d8c2490000000 50 6800020000 } // n = 4, score = 200 // 8d442418 | lea eax, [esp + 0x18] // 8d8c2490000000 | lea ecx, [esp + 0x90] // 50 | push eax // 6800020000 | push 0x200 $sequence_2 = { 8954242c 663dffff 0f84cf000000 83fa01 7f07 } // n = 5, score = 200 // 8954242c | mov dword ptr [esp + 0x2c], edx // 663dffff | cmp ax, 0xffff // 0f84cf000000 | je 0xd5 // 83fa01 | cmp edx, 1 // 7f07 | jg 9 $sequence_3 = { 5d 8b4744 6a00 53 } // n = 4, score = 200 // 5d | pop ebp // 8b4744 | mov eax, dword ptr [edi + 0x44] // 6a00 | push 0 // 53 | push ebx $sequence_4 = { 8b8c2470020000 2bdf 83c304 6a00 53 } // n = 5, score = 200 // 8b8c2470020000 | mov ecx, dword ptr [esp + 0x270] // 2bdf | sub ebx, edi // 83c304 | add ebx, 4 // 6a00 | push 0 // 53 | push ebx $sequence_5 = { 8bf0 b900010000 33c0 8bfe f3ab 83c404 33ff } // n = 7, score = 200 // 8bf0 | mov esi, eax // b900010000 | mov ecx, 0x100 // 33c0 | xor eax, eax // 8bfe | mov edi, esi // f3ab | rep stosd dword ptr es:[edi], eax // 83c404 | add esp, 4 // 33ff | xor edi, edi $sequence_6 = { 2bf9 8d5a08 8bc1 8bf7 8bfb 6a00 } // n = 6, score = 200 // 2bf9 | sub edi, ecx // 8d5a08 | lea ebx, [edx + 8] // 8bc1 | mov eax, ecx // 8bf7 | mov esi, edi // 8bfb | mov edi, ebx // 6a00 | push 0 $sequence_7 = { ff15???????? b908000000 33c0 8d7c2414 8d542434 f3ab } // n = 6, score = 200 // ff15???????? | // b908000000 | mov ecx, 8 // 33c0 | xor eax, eax // 8d7c2414 | lea edi, [esp + 0x14] // 8d542434 | lea edx, [esp + 0x34] // f3ab | rep stosd dword ptr es:[edi], eax $sequence_8 = { 488bcf e8???????? 85c0 7442 488d15726b0000 } // n = 5, score = 100 // 488bcf | dec eax // e8???????? | // 85c0 | arpl cx, bx // 7442 | dec eax // 488d15726b0000 | lea ebp, [0xa507f] $sequence_9 = { 7539 410bc0 488d542458 488d0db3210b00 8905???????? 488d05a61e0100 } // n = 6, score = 100 // 7539 | mov eax, dword ptr [ecx + edi*8 + 0xba200] // 410bc0 | mov cl, byte ptr [eax + esi + 0x3a] // 488d542458 | inc ecx // 488d0db3210b00 | cmp cl, al // 8905???????? | // 488d05a61e0100 | jae 0x6b $sequence_10 = { 48ffc5 488d157cf20000 488bcd e8???????? } // n = 4, score = 100 // 48ffc5 | dec eax // 488d157cf20000 | mov edi, ebx // 488bcd | and ebx, 0x1f // e8???????? | $sequence_11 = { 33d2 8bc1 41f7f2 85d2 7402 2bca } // n = 6, score = 100 // 33d2 | lea ecx, [0x116d] // 8bc1 | jmp 0x14 // 41f7f2 | dec eax // 85d2 | lea ecx, [0x117e] // 7402 | xor edx, edx // 2bca | mov eax, ecx $sequence_12 = { e8???????? 4883c708 4883ff38 7cc2 488b0e } // n = 5, score = 100 // e8???????? | // 4883c708 | mov dword ptr [esp + 0x30], eax // 4883ff38 | dec eax // 7cc2 | lea eax, [ebp - 0x31] // 488b0e | inc ebp $sequence_13 = { 4c8d4597 41b930000000 ba04822200 488bce c744242838000000 4889442420 } // n = 6, score = 100 // 4c8d4597 | mov dword ptr [esp + 0x28], 0x28 // 41b930000000 | mov dword ptr [ebp - 1], 0x40 // ba04822200 | dec eax // 488bce | mov dword ptr [esp + 0x20], eax // c744242838000000 | mov dword ptr [ebp + 3], 0x28 // 4889442420 | dec eax $sequence_14 = { 8bc1 48897c2440 4c897c2448 41f7f0 85d2 7405 } // n = 6, score = 100 // 8bc1 | mov dword ptr [ebp + 7], 0x42000042 // 48897c2440 | dec esp // 4c897c2448 | lea eax, [ebp - 0x69] // 41f7f0 | inc ecx // 85d2 | mov ecx, 0x30 // 7405 | mov edx, 0x228204 $sequence_15 = { 7556 833d????????02 734d 8b8db0030000 0fb7532e 488d8560010000 } // n = 6, score = 100 // 7556 | dec eax // 833d????????02 | // 734d | mov ecx, esi // 8b8db0030000 | mov dword ptr [esp + 0x28], 0x38 // 0fb7532e | dec eax // 488d8560010000 | mov dword ptr [esp + 0x20], eax $sequence_16 = { c744242828000000 c745ff40000000 4889442420 c7450328000000 48c7450742000042 } // n = 5, score = 100 // c744242828000000 | inc ecx // c745ff40000000 | div edx // 4889442420 | test edx, edx // c7450328000000 | je 0xb // 48c7450742000042 | sub ecx, edx $sequence_17 = { 3b0d???????? 7369 4863d9 488d2d7f500a00 488bfb 83e31f 48c1ff05 } // n = 7, score = 100 // 3b0d???????? | // 7369 | dec eax // 4863d9 | add ebx, 5 // 488d2d7f500a00 | dec eax // 488bfb | add eax, esi // 83e31f | mov eax, dword ptr [ebp - 0x4d] // 48c1ff05 | inc ecx $sequence_18 = { 2bc8 750f 488d0d6d110000 ff15???????? eb12 488d0d7e110000 ff15???????? } // n = 7, score = 100 // 2bc8 | inc ecx // 750f | mov eax, ebx // 488d0d6d110000 | sub ecx, eax // ff15???????? | // eb12 | jne 0x11 // 488d0d7e110000 | dec eax // ff15???????? | $sequence_19 = { 7e22 48897b18 48897310 408833 4533c0 488d15cb550100 488bcb } // n = 7, score = 100 // 7e22 | lea esp, [eax - 8] // 48897b18 | inc esp // 48897310 | mov byte ptr [eax + esi + 0x39], al // 408833 | inc ecx // 4533c0 | cmp ch, 1 // 488d15cb550100 | jne 0x34 // 488bcb | dec ebx $sequence_20 = { 8b6c3301 4863c5 4883c305 4803c6 } // n = 4, score = 100 // 8b6c3301 | mov eax, ecx // 4863c5 | dec eax // 4883c305 | mov dword ptr [esp + 0x40], edi // 4803c6 | dec esp $sequence_21 = { 7402 8913 3bd7 410f92c3 418bc3 } // n = 5, score = 100 // 7402 | je 4 // 8913 | mov dword ptr [ebx], edx // 3bd7 | cmp edx, edi // 410f92c3 | inc ecx // 418bc3 | setb bl $sequence_22 = { 448be0 85c0 0f844e010000 488b4c2450 488364242000 488d055d970a00 } // n = 6, score = 100 // 448be0 | mov ecx, 0x20 // 85c0 | mov dword ptr [ebp - 0x2d], eax // 0f844e010000 | dec eax // 488b4c2450 | lea eax, [ebp + 0x67] // 488364242000 | mov edx, 0x22824c // 488d055d970a00 | dec eax $sequence_23 = { 458d60f8 4488443039 4180fd01 752e 4b8b84f900a20b00 8a4c303a 413ac8 } // n = 7, score = 100 // 458d60f8 | mov ecx, dword ptr [ebp + 0x3b0] // 4488443039 | movzx edx, word ptr [ebx + 0x2e] // 4180fd01 | dec eax // 752e | lea eax, [ebp + 0x160] // 4b8b84f900a20b00 | mov ebp, dword ptr [ebx + esi + 1] // 8a4c303a | dec eax // 413ac8 | arpl bp, ax condition: 7 of them and filesize < 1581056 }