rule win_zeus_auto { meta: author = "Felix Bilstein - yara-signator at cocacoding dot com" date = "2026-05-04" 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 = "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 = { 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 = { 885dff 53 53 6a03 } // n = 4, score = 600 // 885dff | mov byte ptr [ebp - 1], bl // 53 | push ebx // 53 | push ebx // 6a03 | push 3 $sequence_2 = { 83e900 741e 49 740c } // n = 4, score = 600 // 83e900 | sub ecx, 0 // 741e | je 0x20 // 49 | dec ecx // 740c | je 0xe $sequence_3 = { 8b0d???????? 03c8 830904 8b0d???????? } // n = 4, score = 600 // 8b0d???????? | // 03c8 | add ecx, eax // 830904 | or dword ptr [ecx], 4 // 8b0d???????? | $sequence_4 = { 83e81c 50 8d461c 50 8d45f0 50 e8???????? } // n = 7, score = 600 // 83e81c | sub eax, 0x1c // 50 | push eax // 8d461c | lea eax, [esi + 0x1c] // 50 | push eax // 8d45f0 | lea eax, [ebp - 0x10] // 50 | push eax // e8???????? | $sequence_5 = { 8d4301 8d75fc e8???????? 8b75fc } // n = 4, score = 600 // 8d4301 | lea eax, [ebx + 1] // 8d75fc | lea esi, [ebp - 4] // e8???????? | // 8b75fc | mov esi, dword ptr [ebp - 4] $sequence_6 = { ebd7 8b4514 85c0 7409 8338ff } // n = 5, score = 600 // ebd7 | jmp 0xffffffd9 // 8b4514 | mov eax, dword ptr [ebp + 0x14] // 85c0 | test eax, eax // 7409 | je 0xb // 8338ff | cmp dword ptr [eax], -1 $sequence_7 = { 885dff 395d0c 7415 ff750c 53 683a040000 ff15???????? } // n = 7, score = 600 // 885dff | mov byte ptr [ebp - 1], bl // 395d0c | cmp dword ptr [ebp + 0xc], ebx // 7415 | je 0x17 // ff750c | push dword ptr [ebp + 0xc] // 53 | push ebx // 683a040000 | push 0x43a // ff15???????? | $sequence_8 = { 891d???????? 891d???????? ffd6 68???????? } // n = 4, score = 500 // 891d???????? | // 891d???????? | // ffd6 | call esi // 68???????? | $sequence_9 = { 8bf3 6810270000 ff35???????? ff15???????? } // n = 4, score = 500 // 8bf3 | mov esi, ebx // 6810270000 | push 0x2710 // ff35???????? | // ff15???????? | $sequence_10 = { e8???????? 84c0 7442 6a10 } // n = 4, score = 500 // e8???????? | // 84c0 | test al, al // 7442 | je 0x44 // 6a10 | push 0x10 $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 = { 5e 8ac3 5b c20800 55 8bec 83e4f8 } // n = 7, score = 300 // 5e | pop esi // 8ac3 | mov al, bl // 5b | pop ebx // c20800 | ret 8 // 55 | push ebp // 8bec | mov ebp, esp // 83e4f8 | and esp, 0xfffffff8 $sequence_14 = { 894736 8d470c 50 c707000e0000 c7470809080002 e8???????? } // n = 6, 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???????? | $sequence_15 = { b001 5b 8be5 5d c3 66833d????????00 56 } // n = 7, score = 200 // b001 | mov al, 1 // 5b | pop ebx // 8be5 | mov esp, ebp // 5d | pop ebp // c3 | ret // 66833d????????00 | // 56 | push esi $sequence_16 = { 0f84ac000000 b809080002 3945f4 7713 } // n = 4, score = 200 // 0f84ac000000 | je 0xb2 // b809080002 | mov eax, 0x2000809 // 3945f4 | cmp dword ptr [ebp - 0xc], eax // 7713 | ja 0x15 $sequence_17 = { 5b 8bc6 c745f809080002 e8???????? 8ad8 f6450c04 7473 } // n = 7, score = 200 // 5b | pop ebx // 8bc6 | mov eax, esi // c745f809080002 | mov dword ptr [ebp - 8], 0x2000809 // e8???????? | // 8ad8 | mov bl, al // f6450c04 | test byte ptr [ebp + 0xc], 4 // 7473 | je 0x75 $sequence_18 = { 68e6010000 68???????? 6809080002 8bc6 50 8d45fc } // n = 6, score = 200 // 68e6010000 | push 0x1e6 // 68???????? | // 6809080002 | push 0x2000809 // 8bc6 | mov eax, esi // 50 | push eax // 8d45fc | lea eax, [ebp - 4] $sequence_19 = { 3d59495351 0f85ca000000 807b0420 0f85c0000000 33c0 } // n = 5, score = 200 // 3d59495351 | cmp eax, 0x51534959 // 0f85ca000000 | jne 0xd0 // 807b0420 | cmp byte ptr [ebx + 4], 0x20 // 0f85c0000000 | jne 0xc6 // 33c0 | xor eax, eax $sequence_20 = { 740c 81fb45415356 0f85b2000000 b365 6a15 } // n = 5, score = 200 // 740c | je 0xe // 81fb45415356 | cmp ebx, 0x56534145 // 0f85b2000000 | jne 0xb8 // b365 | mov bl, 0x65 // 6a15 | push 0x15 $sequence_21 = { 2501000080 7905 48 83c8fe 40 ff75f4 f7d8 } // n = 7, score = 200 // 2501000080 | and eax, 0x80000001 // 7905 | jns 7 // 48 | dec eax // 83c8fe | or eax, 0xfffffffe // 40 | inc eax // ff75f4 | push dword ptr [ebp - 0xc] // f7d8 | neg eax $sequence_22 = { 81fb5d515047 7410 81fb4f4d4156 7408 81fb59495354 7506 } // n = 6, score = 200 // 81fb5d515047 | cmp ebx, 0x4750515d // 7410 | je 0x12 // 81fb4f4d4156 | cmp ebx, 0x56414d4f // 7408 | je 0xa // 81fb59495354 | cmp ebx, 0x54534959 // 7506 | jne 8 condition: 7 of them and filesize < 319488 }