rule win_babuk_auto { meta: author = "Felix Bilstein - yara-signator at cocacoding dot com" date = "2026-09-17" version = "1" description = "Detects win.babuk." 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.babuk" 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 = { ff15???????? 6800000100 e8???????? 83c404 } // n = 4, score = 800 // ff15???????? | // 6800000100 | push 0x10000 // e8???????? | // 83c404 | add esp, 4 $sequence_1 = { 50 ff15???????? 83f803 7502 } // n = 4, score = 800 // 50 | push eax // ff15???????? | // 83f803 | cmp eax, 3 // 7502 | jne 4 $sequence_2 = { 8b4dfc 8b5508 8b44ca04 50 8b0cca 51 e8???????? } // n = 7, score = 600 // 8b4dfc | mov ecx, dword ptr [ebp - 4] // 8b5508 | mov edx, dword ptr [ebp + 8] // 8b44ca04 | mov eax, dword ptr [edx + ecx*8 + 4] // 50 | push eax // 8b0cca | mov ecx, dword ptr [edx + ecx*8] // 51 | push ecx // e8???????? | $sequence_3 = { 8945fc 837dfc0a 0f83dc000000 8b4dfc 8b5508 8b44ca04 } // n = 6, score = 600 // 8945fc | mov dword ptr [ebp - 4], eax // 837dfc0a | cmp dword ptr [ebp - 4], 0xa // 0f83dc000000 | jae 0xe2 // 8b4dfc | mov ecx, dword ptr [ebp - 4] // 8b5508 | mov edx, dword ptr [ebp + 8] // 8b44ca04 | mov eax, dword ptr [edx + ecx*8 + 4] $sequence_4 = { 8bec 8b4508 25ff000000 b901000000 } // n = 4, score = 600 // 8bec | mov ebp, esp // 8b4508 | mov eax, dword ptr [ebp + 8] // 25ff000000 | and eax, 0xff // b901000000 | mov ecx, 1 $sequence_5 = { b908000000 6bf100 8b45ec 8b55f0 b11a } // n = 5, score = 600 // b908000000 | mov ecx, 8 // 6bf100 | imul esi, ecx, 0 // 8b45ec | mov eax, dword ptr [ebp - 0x14] // 8b55f0 | mov edx, dword ptr [ebp - 0x10] // b11a | mov cl, 0x1a $sequence_6 = { eb09 8b45fc 83c002 8945fc 837dfc0a 0f83dc000000 } // n = 6, score = 600 // eb09 | jmp 0xb // 8b45fc | mov eax, dword ptr [ebp - 4] // 83c002 | add eax, 2 // 8945fc | mov dword ptr [ebp - 4], eax // 837dfc0a | cmp dword ptr [ebp - 4], 0xa // 0f83dc000000 | jae 0xe2 $sequence_7 = { 50 e8???????? 83c408 8945ec 8955f0 b908000000 6bf100 } // n = 7, score = 600 // 50 | push eax // e8???????? | // 83c408 | add esp, 8 // 8945ec | mov dword ptr [ebp - 0x14], eax // 8955f0 | mov dword ptr [ebp - 0x10], edx // b908000000 | mov ecx, 8 // 6bf100 | imul esi, ecx, 0 $sequence_8 = { 6a00 8b45a4 50 6a01 8b4da8 51 } // n = 6, score = 600 // 6a00 | push 0 // 8b45a4 | mov eax, dword ptr [ebp - 0x5c] // 50 | push eax // 6a01 | push 1 // 8b4da8 | mov ecx, dword ptr [ebp - 0x58] // 51 | push ecx $sequence_9 = { 8d148d04000000 8955ec 8b45e0 8b4dec 8d540102 52 6a00 } // n = 7, score = 600 // 8d148d04000000 | lea edx, [ecx*4 + 4] // 8955ec | mov dword ptr [ebp - 0x14], edx // 8b45e0 | mov eax, dword ptr [ebp - 0x20] // 8b4dec | mov ecx, dword ptr [ebp - 0x14] // 8d540102 | lea edx, [ecx + eax + 2] // 52 | push edx // 6a00 | push 0 $sequence_10 = { 8b8c8508fdffff 51 ff15???????? eb02 eb21 6800800000 } // n = 6, score = 600 // 8b8c8508fdffff | mov ecx, dword ptr [ebp + eax*4 - 0x2f8] // 51 | push ecx // ff15???????? | // eb02 | jmp 4 // eb21 | jmp 0x23 // 6800800000 | push 0x8000 $sequence_11 = { b804000000 6bc800 8b5508 c7040a65787061 b804000000 } // n = 5, score = 600 // b804000000 | mov eax, 4 // 6bc800 | imul ecx, eax, 0 // 8b5508 | mov edx, dword ptr [ebp + 8] // c7040a65787061 | mov dword ptr [edx + ecx], 0x61707865 // b804000000 | mov eax, 4 $sequence_12 = { c7040100000000 c744010400000000 ba08000000 6bc200 8b4d08 8b540104 52 } // n = 7, score = 600 // c7040100000000 | mov dword ptr [ecx + eax], 0 // c744010400000000 | mov dword ptr [ecx + eax + 4], 0 // ba08000000 | mov edx, 8 // 6bc200 | imul eax, edx, 0 // 8b4d08 | mov ecx, dword ptr [ebp + 8] // 8b540104 | mov edx, dword ptr [ecx + eax + 4] // 52 | push edx $sequence_13 = { 8b0cca 51 e8???????? 83c408 8945f4 8955f8 } // n = 6, score = 600 // 8b0cca | mov ecx, dword ptr [edx + ecx*8] // 51 | push ecx // e8???????? | // 83c408 | add esp, 8 // 8945f4 | mov dword ptr [ebp - 0xc], eax // 8955f8 | mov dword ptr [ebp - 8], edx $sequence_14 = { e8???????? 83c408 8b4d18 8b5508 89048a 8b4514 8b4d08 } // n = 7, score = 600 // e8???????? | // 83c408 | add esp, 8 // 8b4d18 | mov ecx, dword ptr [ebp + 0x18] // 8b5508 | mov edx, dword ptr [ebp + 8] // 89048a | mov dword ptr [edx + ecx*4], eax // 8b4514 | mov eax, dword ptr [ebp + 0x14] // 8b4d08 | mov ecx, dword ptr [ebp + 8] $sequence_15 = { 8b5508 c7040a00000000 c7440a0400000000 c745fc00000000 eb09 } // n = 5, score = 600 // 8b5508 | mov edx, dword ptr [ebp + 8] // c7040a00000000 | mov dword ptr [edx + ecx], 0 // c7440a0400000000 | mov dword ptr [edx + ecx + 4], 0 // c745fc00000000 | mov dword ptr [ebp - 4], 0 // eb09 | jmp 0xb condition: 7 of them and filesize < 183296 }