rule win_silence_auto { meta: author = "Felix Bilstein - yara-signator at cocacoding dot com" date = "2026-09-17" version = "1" description = "Detects win.silence." 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.silence" 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 = { 8d45fc 50 6a00 6a00 68???????? c745fc00000000 } // n = 6, score = 1800 // 8d45fc | lea eax, [ebp - 4] // 50 | push eax // 6a00 | push 0 // 6a00 | push 0 // 68???????? | // c745fc00000000 | mov dword ptr [ebp - 4], 0 $sequence_1 = { cc 8325????????00 c3 6a08 68???????? } // n = 5, score = 1800 // cc | int3 // 8325????????00 | // c3 | ret // 6a08 | push 8 // 68???????? | $sequence_2 = { 40 84c9 75f4 eb05 } // n = 4, score = 1800 // 40 | inc eax // 84c9 | test cl, cl // 75f4 | jne 0xfffffff6 // eb05 | jmp 7 $sequence_3 = { 683f020f00 6a00 68???????? 6801000080 ff15???????? 68???????? } // n = 6, score = 1700 // 683f020f00 | push 0xf023f // 6a00 | push 0 // 68???????? | // 6801000080 | push 0x80000001 // ff15???????? | // 68???????? | $sequence_4 = { ff15???????? 6a00 6800000004 6a00 6a00 } // n = 5, score = 1600 // ff15???????? | // 6a00 | push 0 // 6800000004 | push 0x4000000 // 6a00 | push 0 // 6a00 | push 0 $sequence_5 = { 68???????? ffd6 8b45fc 85c0 } // n = 4, score = 1600 // 68???????? | // ffd6 | call esi // 8b45fc | mov eax, dword ptr [ebp - 4] // 85c0 | test eax, eax $sequence_6 = { 46 56 8d85f8feffff 50 6a01 } // n = 5, score = 1600 // 46 | inc esi // 56 | push esi // 8d85f8feffff | lea eax, [ebp - 0x108] // 50 | push eax // 6a01 | push 1 $sequence_7 = { 6801000080 ff15???????? 56 8d85f8feffff } // n = 4, score = 1600 // 6801000080 | push 0x80000001 // ff15???????? | // 56 | push esi // 8d85f8feffff | lea eax, [ebp - 0x108] $sequence_8 = { f3c3 e9???????? e8???????? e9???????? 6a14 68???????? } // n = 6, score = 1600 // f3c3 | ret // e9???????? | // e8???????? | // e9???????? | // 6a14 | push 0x14 // 68???????? | $sequence_9 = { 3acb 740a 8a4801 40 84c9 } // n = 5, score = 1400 // 3acb | cmp cl, bl // 740a | je 0xc // 8a4801 | mov cl, byte ptr [eax + 1] // 40 | inc eax // 84c9 | test cl, cl $sequence_10 = { 5b 5d c3 c60200 } // n = 4, score = 1400 // 5b | pop ebx // 5d | pop ebp // c3 | ret // c60200 | mov byte ptr [edx], 0 $sequence_11 = { 8bd8 68???????? 53 ff15???????? 6a00 6a00 } // n = 6, score = 1400 // 8bd8 | test cl, cl // 68???????? | // 53 | jne 0xfffffff8 // ff15???????? | // 6a00 | jmp 0x13 // 6a00 | cmp byte ptr [eax], 0 $sequence_12 = { 6a00 8bf8 6a00 57 ff15???????? 8d45fc } // n = 6, score = 1400 // 6a00 | mov bl, byte ptr [edx + 1] // 8bf8 | test cl, cl // 6a00 | jne 0xfffffff6 // 57 | jmp 0x11 // ff15???????? | // 8d45fc | cmp byte ptr [eax], 0 $sequence_13 = { 75f4 eb0d 803800 7408 8a5a01 42 84db } // n = 7, score = 1400 // 75f4 | jne 0xfffffff6 // eb0d | jmp 0xf // 803800 | cmp byte ptr [eax], 0 // 7408 | je 0xa // 8a5a01 | mov bl, byte ptr [edx + 1] // 42 | inc edx // 84db | test bl, bl $sequence_14 = { 50 ff15???????? 8bf0 6a00 85f6 } // n = 5, score = 1400 // 50 | push eax // ff15???????? | // 8bf0 | mov esi, eax // 6a00 | push 0 // 85f6 | test esi, esi $sequence_15 = { 6800080000 8d85bcf7ffff 50 56 ff15???????? } // n = 5, score = 1200 // 6800080000 | push 0x800 // 8d85bcf7ffff | lea eax, [ebp - 0x844] // 50 | push eax // 56 | push esi // ff15???????? | $sequence_16 = { 8b85b8f7ffff 85c0 75b6 ffb5acf7ffff } // n = 4, score = 1200 // 8b85b8f7ffff | mov eax, dword ptr [ebp - 0x848] // 85c0 | test eax, eax // 75b6 | jne 0xffffffb8 // ffb5acf7ffff | push dword ptr [ebp - 0x854] $sequence_17 = { ff5004 8b46f8 0346f4 57 } // n = 4, score = 1100 // ff5004 | call dword ptr [eax + 4] // 8b46f8 | mov eax, dword ptr [esi - 8] // 0346f4 | add eax, dword ptr [esi - 0xc] // 57 | push edi $sequence_18 = { 03d7 3b56f0 7611 8b46ec } // n = 4, score = 1100 // 03d7 | add edx, edi // 3b56f0 | cmp edx, dword ptr [esi - 0x10] // 7611 | jbe 0x13 // 8b46ec | mov eax, dword ptr [esi - 0x14] $sequence_19 = { e8???????? 8b4ef4 8bc7 2bc1 } // n = 4, score = 1100 // e8???????? | // 8b4ef4 | mov ecx, dword ptr [esi - 0xc] // 8bc7 | mov eax, edi // 2bc1 | sub eax, ecx $sequence_20 = { 8b35???????? ffd6 ff7704 ffd6 ff770c ffd6 } // n = 6, score = 1100 // 8b35???????? | // ffd6 | call esi // ff7704 | push dword ptr [edi + 4] // ffd6 | call esi // ff770c | push dword ptr [edi + 0xc] // ffd6 | call esi $sequence_21 = { ff5210 8b17 8bcf ff5208 } // n = 4, score = 1100 // ff5210 | call dword ptr [edx + 0x10] // 8b17 | mov edx, dword ptr [edi] // 8bcf | mov ecx, edi // ff5208 | call dword ptr [edx + 8] $sequence_22 = { e8???????? 83c41c 895ef8 897ef0 } // n = 4, score = 1100 // e8???????? | // 83c41c | add esp, 0x1c // 895ef8 | mov dword ptr [esi - 8], ebx // 897ef0 | mov dword ptr [esi - 0x10], edi $sequence_23 = { 85c9 7412 8b01 52 8d95f0fdffff 52 ff10 } // n = 7, score = 1100 // 85c9 | test ecx, ecx // 7412 | je 0x14 // 8b01 | mov eax, dword ptr [ecx] // 52 | push edx // 8d95f0fdffff | lea edx, [ebp - 0x210] // 52 | push edx // ff10 | call dword ptr [eax] $sequence_24 = { e8???????? ff37 8b35???????? ffd6 } // n = 4, score = 1100 // e8???????? | // ff37 | push dword ptr [edi] // 8b35???????? | // ffd6 | call esi $sequence_25 = { ff15???????? 488d542430 488d8c2440020000 ff15???????? } // n = 4, score = 500 // ff15???????? | // 488d542430 | dec eax // 488d8c2440020000 | lea edx, [esp + 0x30] // ff15???????? | $sequence_26 = { e8???????? ba00040000 b940000000 ff15???????? } // n = 4, score = 500 // e8???????? | // ba00040000 | shl eax, cl // b940000000 | add ecx, eax // ff15???????? | $sequence_27 = { ff15???????? ba180c0000 b940000000 ff15???????? } // n = 4, score = 500 // ff15???????? | // ba180c0000 | mov edx, 0xc18 // b940000000 | mov ecx, 0x40 // ff15???????? | $sequence_28 = { 8b05???????? d3e0 8b0d???????? 03c8 } // n = 4, score = 500 // 8b05???????? | // d3e0 | movzx ecx, al // 8b0d???????? | // 03c8 | shl eax, cl $sequence_29 = { d3f8 0fb60d???????? d3e0 85c0 } // n = 4, score = 500 // d3f8 | mov edx, 0x400 // 0fb60d???????? | // d3e0 | mov ecx, 0x40 // 85c0 | sar eax, cl $sequence_30 = { 99 83e203 03c2 c1f802 89442448 } // n = 5, score = 500 // 99 | dec eax // 83e203 | lea ecx, [esp + 0x240] // 03c2 | cdq // c1f802 | and edx, 3 // 89442448 | add eax, edx $sequence_31 = { d3e8 0fb6c8 8b05???????? d3e0 } // n = 4, score = 500 // d3e8 | sar eax, 2 // 0fb6c8 | mov dword ptr [esp + 0x40], eax // 8b05???????? | // d3e0 | shr eax, cl $sequence_32 = { ff15???????? 41b804010000 488d542430 488d4c2430 ff15???????? 85c0 } // n = 6, score = 500 // ff15???????? | // 41b804010000 | shl eax, cl // 488d542430 | test eax, eax // 488d4c2430 | inc ecx // ff15???????? | // 85c0 | mov eax, 0x104 $sequence_33 = { 7507 68???????? ffd7 6a00 6a00 6a01 6a00 } // n = 7, score = 400 // 7507 | jne 9 // 68???????? | // ffd7 | call edi // 6a00 | push 0 // 6a00 | push 0 // 6a01 | push 1 // 6a00 | push 0 $sequence_34 = { ff15???????? c20800 53 8b1d???????? 57 0f57c0 } // n = 6, score = 400 // ff15???????? | // c20800 | ret 8 // 53 | push ebx // 8b1d???????? | // 57 | push edi // 0f57c0 | xorps xmm0, xmm0 $sequence_35 = { ff15???????? 68c0d40100 ff15???????? e9???????? } // n = 4, score = 400 // ff15???????? | // 68c0d40100 | inc eax // ff15???????? | // e9???????? | $sequence_36 = { 55 8bec ff4d08 755d 833d????????04 7554 } // n = 6, score = 400 // 55 | push ebp // 8bec | mov ebp, esp // ff4d08 | dec dword ptr [ebp + 8] // 755d | jne 0x5f // 833d????????04 | // 7554 | jne 0x56 $sequence_37 = { c705????????00000000 c705????????00000000 c705????????00000000 ffd3 8b3d???????? } // n = 5, score = 400 // c705????????00000000 | // c705????????00000000 | // c705????????00000000 | // ffd3 | call ebx // 8b3d???????? | $sequence_38 = { c705????????04000000 ff15???????? 85c0 750b 68???????? } // n = 5, score = 400 // c705????????04000000 | // ff15???????? | // 85c0 | test eax, eax // 750b | jne 0xd // 68???????? | $sequence_39 = { 85c0 750e 68???????? ff15???????? c20800 53 } // n = 6, score = 400 // 85c0 | test eax, eax // 750e | jne 0x10 // 68???????? | // ff15???????? | // c20800 | ret 8 // 53 | push ebx $sequence_40 = { 68???????? 68???????? ff15???????? a3???????? 85c0 750e 68???????? } // n = 7, score = 400 // 68???????? | // 68???????? | // ff15???????? | // a3???????? | // 85c0 | test eax, eax // 750e | jne 0x10 // 68???????? | $sequence_41 = { 8d0441 33d2 b905000000 f7f1 } // n = 4, score = 400 // 8d0441 | test cl, cl // 33d2 | jne 0xfffffff8 // b905000000 | jmp 0x13 // f7f1 | cmp byte ptr [eax], 0 $sequence_42 = { 750b 68???????? ff15???????? ff35???????? ff15???????? } // n = 5, score = 400 // 750b | jne 0xd // 68???????? | // ff15???????? | // ff35???????? | // ff15???????? | $sequence_43 = { 50 6a00 ff15???????? 6a00 6a00 68???????? ff15???????? } // n = 7, score = 200 // 50 | mov ebx, eax // 6a00 | push ebx // ff15???????? | // 6a00 | push 0 // 6a00 | push 0 // 68???????? | // ff15???????? | $sequence_44 = { 8945e0 833d????????00 7511 8b55ec 0355ec 7509 } // n = 6, score = 100 // 8945e0 | mov edi, eax // 833d????????00 | // 7511 | push 0 // 8b55ec | push edi // 0355ec | lea eax, [ebp - 4] // 7509 | push 0 $sequence_45 = { 8945c0 e8???????? 8945a8 e8???????? 8945ac e8???????? 8945b0 } // n = 7, score = 100 // 8945c0 | mov edi, eax // e8???????? | // 8945a8 | push 0 // e8???????? | // 8945ac | push edi // e8???????? | // 8945b0 | lea eax, [ebp - 4] condition: 7 of them and filesize < 70128640 }