rule win_ghost_rat_auto { meta: author = "Felix Bilstein - yara-signator at cocacoding dot com" date = "2026-09-17" version = "1" description = "Detects win.ghost_rat." 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.ghost_rat" 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 = { 6a01 56 ff15???????? 5e c20800 } // n = 5, score = 500 // 6a01 | push 1 // 56 | push esi // ff15???????? | // 5e | pop esi // c20800 | ret 8 $sequence_1 = { 8b400c 85c0 7505 a1???????? 50 8bce e8???????? } // n = 7, score = 500 // 8b400c | mov eax, dword ptr [eax + 0xc] // 85c0 | test eax, eax // 7505 | jne 7 // a1???????? | // 50 | push eax // 8bce | mov ecx, esi // e8???????? | $sequence_2 = { 8bd9 e8???????? 8b4d08 3bc8 } // n = 4, score = 500 // 8bd9 | mov ebx, ecx // e8???????? | // 8b4d08 | mov ecx, dword ptr [ebp + 8] // 3bc8 | cmp ecx, eax $sequence_3 = { 6a6b 8bce e8???????? 5f } // n = 4, score = 400 // 6a6b | push 0x6b // 8bce | mov ecx, esi // e8???????? | // 5f | pop edi $sequence_4 = { df6df4 83ec08 dc0d???????? dd1c24 } // n = 4, score = 400 // df6df4 | fild qword ptr [ebp - 0xc] // 83ec08 | sub esp, 8 // dc0d???????? | // dd1c24 | fstp qword ptr [esp] $sequence_5 = { 5d c20400 894df4 c745f800000000 df6df4 } // n = 5, score = 400 // 5d | pop ebp // c20400 | ret 4 // 894df4 | mov dword ptr [ebp - 0xc], ecx // c745f800000000 | mov dword ptr [ebp - 8], 0 // df6df4 | fild qword ptr [ebp - 0xc] $sequence_6 = { e9???????? 8d45dc 50 681f000200 } // n = 4, score = 300 // e9???????? | // 8d45dc | lea eax, [ebp - 0x24] // 50 | push eax // 681f000200 | push 0x2001f $sequence_7 = { ff75e8 e8???????? 8bce e8???????? 6a00 8bce } // n = 6, score = 300 // ff75e8 | push dword ptr [ebp - 0x18] // e8???????? | // 8bce | mov ecx, esi // e8???????? | // 6a00 | push 0 // 8bce | mov ecx, esi $sequence_8 = { 68???????? 50 6802000080 e8???????? 83c41c 5f } // n = 6, score = 300 // 68???????? | // 50 | push eax // 6802000080 | push 0x80000002 // e8???????? | // 83c41c | add esp, 0x1c // 5f | pop edi $sequence_9 = { 83c40c 46 750b 5f 5e } // n = 5, score = 300 // 83c40c | add esp, 0xc // 46 | inc esi // 750b | jne 0xd // 5f | pop edi // 5e | pop esi $sequence_10 = { 84c0 7505 83ceff eb32 } // n = 4, score = 300 // 84c0 | test al, al // 7505 | jne 7 // 83ceff | or esi, 0xffffffff // eb32 | jmp 0x34 $sequence_11 = { 6a00 6a00 68???????? 68???????? 6a00 6a00 c705????????20010000 } // n = 7, score = 300 // 6a00 | push 0 // 6a00 | push 0 // 68???????? | // 68???????? | // 6a00 | push 0 // 6a00 | push 0 // c705????????20010000 | $sequence_12 = { e9???????? 8b4df0 83c154 e9???????? 8b4df0 83c17c e9???????? } // n = 7, score = 300 // e9???????? | // 8b4df0 | mov ecx, dword ptr [ebp - 0x10] // 83c154 | add ecx, 0x54 // e9???????? | // 8b4df0 | mov ecx, dword ptr [ebp - 0x10] // 83c17c | add ecx, 0x7c // e9???????? | $sequence_13 = { ff75dc ff15???????? 85c0 7507 c745e401000000 834dfcff } // n = 6, score = 300 // ff75dc | push dword ptr [ebp - 0x24] // ff15???????? | // 85c0 | test eax, eax // 7507 | jne 9 // c745e401000000 | mov dword ptr [ebp - 0x1c], 1 // 834dfcff | or dword ptr [ebp - 4], 0xffffffff $sequence_14 = { 894c2438 50 6a00 c744243c01000000 } // n = 4, score = 300 // 894c2438 | mov dword ptr [esp + 0x38], ecx // 50 | push eax // 6a00 | push 0 // c744243c01000000 | mov dword ptr [esp + 0x3c], 1 $sequence_15 = { ff15???????? 40 50 ff15???????? 59 } // n = 5, score = 300 // ff15???????? | // 40 | inc eax // 50 | push eax // ff15???????? | // 59 | pop ecx $sequence_16 = { 5f 5e 33c0 5b 83c454 } // n = 5, score = 300 // 5f | pop edi // 5e | pop esi // 33c0 | xor eax, eax // 5b | pop ebx // 83c454 | add esp, 0x54 $sequence_17 = { 8dbd85feffff f3ab 66ab aa } // n = 4, score = 300 // 8dbd85feffff | lea edi, [ebp - 0x17b] // f3ab | rep stosd dword ptr es:[edi], eax // 66ab | stosw word ptr es:[edi], ax // aa | stosb byte ptr es:[edi], al $sequence_18 = { 8d85c0feffff 50 57 ff15???????? 8bf8 } // n = 5, score = 300 // 8d85c0feffff | lea eax, [ebp - 0x140] // 50 | push eax // 57 | push edi // ff15???????? | // 8bf8 | mov edi, eax $sequence_19 = { 85db 750d 5f 5e 5d 32c0 5b } // n = 7, score = 300 // 85db | test ebx, ebx // 750d | jne 0xf // 5f | pop edi // 5e | pop esi // 5d | pop ebp // 32c0 | xor al, al // 5b | pop ebx $sequence_20 = { f2ae f7d1 49 7509 5f 5e 5b } // n = 7, score = 300 // f2ae | repne scasb al, byte ptr es:[edi] // f7d1 | not ecx // 49 | dec ecx // 7509 | jne 0xb // 5f | pop edi // 5e | pop esi // 5b | pop ebx $sequence_21 = { 50 e8???????? 83c40c ff7508 6a40 ff15???????? } // n = 6, score = 300 // 50 | push eax // e8???????? | // 83c40c | add esp, 0xc // ff7508 | push dword ptr [ebp + 8] // 6a40 | push 0x40 // ff15???????? | $sequence_22 = { ff15???????? 6a01 ff7620 ff15???????? 8b4e04 e8???????? 33c0 } // n = 7, score = 300 // ff15???????? | // 6a01 | push 1 // ff7620 | push dword ptr [esi + 0x20] // ff15???????? | // 8b4e04 | mov ecx, dword ptr [esi + 4] // e8???????? | // 33c0 | xor eax, eax $sequence_23 = { 6a00 50 c744241c00000000 ff15???????? 8b4e20 6a00 } // n = 6, score = 300 // 6a00 | push 0 // 50 | push eax // c744241c00000000 | mov dword ptr [esp + 0x1c], 0 // ff15???????? | // 8b4e20 | mov ecx, dword ptr [esi + 0x20] // 6a00 | push 0 $sequence_24 = { 7408 8d4e10 e8???????? 6a6b 8bce } // n = 5, score = 300 // 7408 | je 0xa // 8d4e10 | lea ecx, [esi + 0x10] // e8???????? | // 6a6b | push 0x6b // 8bce | mov ecx, esi $sequence_25 = { c7014c696272 83e9fc c70161727941 83e9fc c70100000000 } // n = 5, score = 200 // c7014c696272 | mov dword ptr [ecx], 0x7262694c // 83e9fc | sub ecx, -4 // c70161727941 | mov dword ptr [ecx], 0x41797261 // 83e9fc | sub ecx, -4 // c70100000000 | mov dword ptr [ecx], 0 $sequence_26 = { 8b760c 8b761c 8b4608 8b7e20 8b36 813f6b006500 } // n = 6, score = 200 // 8b760c | mov esi, dword ptr [esi + 0xc] // 8b761c | mov esi, dword ptr [esi + 0x1c] // 8b4608 | mov eax, dword ptr [esi + 8] // 8b7e20 | mov edi, dword ptr [esi + 0x20] // 8b36 | mov esi, dword ptr [esi] // 813f6b006500 | cmp dword ptr [edi], 0x65006b $sequence_27 = { 8b7e20 8b36 813f6b006500 7406 813f4b004500 75e8 } // n = 6, score = 200 // 8b7e20 | mov edi, dword ptr [esi + 0x20] // 8b36 | mov esi, dword ptr [esi] // 813f6b006500 | cmp dword ptr [edi], 0x65006b // 7406 | je 8 // 813f4b004500 | cmp dword ptr [edi], 0x45004b // 75e8 | jne 0xffffffea $sequence_28 = { c7014c6f6164 83e9fc c7014c696272 83e9fc } // n = 4, score = 200 // c7014c6f6164 | mov dword ptr [ecx], 0x64616f4c // 83e9fc | sub ecx, -4 // c7014c696272 | mov dword ptr [ecx], 0x7262694c // 83e9fc | sub ecx, -4 $sequence_29 = { 8b4508 03440a0c 50 8b4d0c ff511c eb9b } // n = 6, score = 100 // 8b4508 | mov eax, dword ptr [ebp + 8] // 03440a0c | add eax, dword ptr [edx + ecx + 0xc] // 50 | push eax // 8b4d0c | mov ecx, dword ptr [ebp + 0xc] // ff511c | call dword ptr [ecx + 0x1c] // eb9b | jmp 0xffffff9d $sequence_30 = { 8b55fc 83c208 8955f0 c745f401000000 } // n = 4, score = 100 // 8b55fc | mov edx, dword ptr [ebp - 4] // 83c208 | add edx, 8 // 8955f0 | mov dword ptr [ebp - 0x10], edx // c745f401000000 | mov dword ptr [ebp - 0xc], 1 $sequence_31 = { 83c101 898d6cffffff 8b956cffffff 3b55d0 7d21 8b8558ffffff } // n = 6, score = 100 // 83c101 | add ecx, 1 // 898d6cffffff | mov dword ptr [ebp - 0x94], ecx // 8b956cffffff | mov edx, dword ptr [ebp - 0x94] // 3b55d0 | cmp edx, dword ptr [ebp - 0x30] // 7d21 | jge 0x23 // 8b8558ffffff | mov eax, dword ptr [ebp - 0xa8] $sequence_32 = { 894594 c3 eb08 58 } // n = 4, score = 100 // 894594 | mov dword ptr [ebp - 0x6c], eax // c3 | ret // eb08 | jmp 0xa // 58 | pop eax condition: 7 of them and filesize < 357376 }