rule win_zeus_auto { meta: author = "Felix Bilstein - yara-signator at cocacoding dot com" date = "2026-09-17" version = "1" description = "Detects win.zeus." 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.zeus" 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 = { eb58 833f00 7651 8b5f08 } // n = 4, score = 700 // eb58 | jmp 0x5a // 833f00 | cmp dword ptr [edi], 0 // 7651 | jbe 0x53 // 8b5f08 | mov ebx, dword ptr [edi + 8] $sequence_1 = { 8b4804 81e1000000e0 394c240c 740d } // n = 4, score = 600 // 8b4804 | mov ecx, dword ptr [eax + 4] // 81e1000000e0 | and ecx, 0xe0000000 // 394c240c | cmp dword ptr [esp + 0xc], ecx // 740d | je 0xf $sequence_2 = { c6451700 8b5d10 3bde 7503 8d5d10 39750c } // n = 6, score = 600 // c6451700 | mov byte ptr [ebp + 0x17], 0 // 8b5d10 | mov ebx, dword ptr [ebp + 0x10] // 3bde | cmp ebx, esi // 7503 | jne 5 // 8d5d10 | lea ebx, [ebp + 0x10] // 39750c | cmp dword ptr [ebp + 0xc], esi $sequence_3 = { 8d7708 8975fc e8???????? 8d4720 } // n = 4, score = 600 // 8d7708 | lea esi, [edi + 8] // 8975fc | mov dword ptr [ebp - 4], esi // e8???????? | // 8d4720 | lea eax, [edi + 0x20] $sequence_4 = { eb21 ff7514 8bc6 57 } // n = 4, score = 600 // eb21 | jmp 0x23 // ff7514 | push dword ptr [ebp + 0x14] // 8bc6 | mov eax, esi // 57 | push edi $sequence_5 = { 84c0 7467 8b5d10 83e301 33ff 3bdf } // n = 6, score = 600 // 84c0 | test al, al // 7467 | je 0x69 // 8b5d10 | mov ebx, dword ptr [ebp + 0x10] // 83e301 | and ebx, 1 // 33ff | xor edi, edi // 3bdf | cmp ebx, edi $sequence_6 = { 8d7708 83c720 57 8d45f4 50 8d45f8 50 } // n = 7, score = 600 // 8d7708 | lea esi, [edi + 8] // 83c720 | add edi, 0x20 // 57 | push edi // 8d45f4 | lea eax, [ebp - 0xc] // 50 | push eax // 8d45f8 | lea eax, [ebp - 8] // 50 | push eax $sequence_7 = { e8???????? 8b4808 8b32 8d4c3110 81f90000a000 7715 8918 } // n = 7, score = 600 // e8???????? | // 8b4808 | mov ecx, dword ptr [eax + 8] // 8b32 | mov esi, dword ptr [edx] // 8d4c3110 | lea ecx, [ecx + esi + 0x10] // 81f90000a000 | cmp ecx, 0xa00000 // 7715 | ja 0x17 // 8918 | mov dword ptr [eax], ebx $sequence_8 = { 891d???????? 891d???????? ffd6 68???????? } // n = 4, score = 500 // 891d???????? | // 891d???????? | // ffd6 | call esi // 68???????? | $sequence_9 = { e8???????? 84c0 7442 6a10 } // n = 4, score = 500 // e8???????? | // 84c0 | test al, al // 7442 | je 0x44 // 6a10 | push 0x10 $sequence_10 = { 8bf3 6810270000 ff35???????? ff15???????? } // n = 4, score = 500 // 8bf3 | mov esi, ebx // 6810270000 | push 0x2710 // ff35???????? | // ff15???????? | $sequence_11 = { 8d8db0fdffff e8???????? 8ad8 84db } // n = 4, score = 400 // 8d8db0fdffff | lea ecx, [ebp - 0x250] // e8???????? | // 8ad8 | mov bl, al // 84db | test bl, bl $sequence_12 = { c20400 55 8bec f6451802 } // n = 4, score = 300 // c20400 | ret 4 // 55 | push ebp // 8bec | mov ebp, esp // f6451802 | test byte ptr [ebp + 0x18], 2 $sequence_13 = { 56 ff15???????? 5e 8ac3 5b c20800 55 } // n = 7, score = 300 // 56 | push esi // ff15???????? | // 5e | pop esi // 8ac3 | mov al, bl // 5b | pop ebx // c20800 | ret 8 // 55 | push ebp $sequence_14 = { 8d75a8 b8d5000000 e8???????? 68e6010000 68???????? 6809080002 } // n = 6, score = 200 // 8d75a8 | lea esi, [ebp - 0x58] // b8d5000000 | mov eax, 0xd5 // e8???????? | // 68e6010000 | push 0x1e6 // 68???????? | // 6809080002 | push 0x2000809 $sequence_15 = { b9???????? 56 57 33f6 56 50 68???????? } // n = 7, score = 200 // b9???????? | // 56 | push esi // 57 | push edi // 33f6 | xor esi, esi // 56 | push esi // 50 | push eax // 68???????? | $sequence_16 = { 6809080002 8bc6 50 8d45fc 50 e8???????? } // n = 6, score = 200 // 6809080002 | push 0x2000809 // 8bc6 | mov eax, esi // 50 | push eax // 8d45fc | lea eax, [ebp - 4] // 50 | push eax // e8???????? | $sequence_17 = { eb18 81fb5a5c4156 740c 81fb45415356 } // n = 4, score = 200 // eb18 | jmp 0x1a // 81fb5a5c4156 | cmp ebx, 0x56415c5a // 740c | je 0xe // 81fb45415356 | cmp ebx, 0x56534145 $sequence_18 = { 894736 8d470c 50 c707000e0000 c7470809080002 e8???????? 83674200 } // n = 7, score = 200 // 894736 | mov dword ptr [edi + 0x36], eax // 8d470c | lea eax, [edi + 0xc] // 50 | push eax // c707000e0000 | mov dword ptr [edi], 0xe00 // c7470809080002 | mov dword ptr [edi + 8], 0x2000809 // e8???????? | // 83674200 | and dword ptr [edi + 0x42], 0 $sequence_19 = { 3d59495351 0f85ca000000 807b0420 0f85c0000000 33c0 83c6fb } // n = 6, score = 200 // 3d59495351 | cmp eax, 0x51534959 // 0f85ca000000 | jne 0xd0 // 807b0420 | cmp byte ptr [ebx + 4], 0x20 // 0f85c0000000 | jne 0xc6 // 33c0 | xor eax, eax // 83c6fb | add esi, -5 $sequence_20 = { 83fe06 0f86e3000000 8b03 3509080002 3d5c5b4550 } // n = 5, score = 200 // 83fe06 | cmp esi, 6 // 0f86e3000000 | jbe 0xe9 // 8b03 | mov eax, dword ptr [ebx] // 3509080002 | xor eax, 0x2000809 // 3d5c5b4550 | cmp eax, 0x50455b5c $sequence_21 = { 84c0 0f84ac000000 b809080002 3945f4 7713 807d0801 } // n = 6, score = 200 // 84c0 | test al, al // 0f84ac000000 | je 0xb2 // b809080002 | mov eax, 0x2000809 // 3945f4 | cmp dword ptr [ebp - 0xc], eax // 7713 | ja 0x15 // 807d0801 | cmp byte ptr [ebp + 8], 1 $sequence_22 = { 83fe04 0f82ec000000 8b1b 81f309080002 } // n = 4, score = 200 // 83fe04 | cmp esi, 4 // 0f82ec000000 | jb 0xf2 // 8b1b | mov ebx, dword ptr [ebx] // 81f309080002 | xor ebx, 0x2000809 condition: 7 of them and filesize < 319488 }