Actor(s): Lazarus Group
There is no description at this point.
rule win_lazarloader_auto { meta: author = "Felix Bilstein - yara-signator at cocacoding dot com" date = "2026-05-04" version = "1" description = "Detects win.lazarloader." 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.lazarloader" 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 = { 48894de8 488945f0 488d15a0bd0000 b805000000 894520 894528 } // n = 6, score = 100 // 48894de8 | dec eax // 488945f0 | test ebx, ebx // 488d15a0bd0000 | jne 0x34e // b805000000 | dec eax // 894520 | mov eax, edi // 894528 | dec ecx $sequence_1 = { 488bd7 4c8d05fecd0000 83e23f 488bcf } // n = 4, score = 100 // 488bd7 | dec eax // 4c8d05fecd0000 | cmp ecx, eax // 83e23f | dec eax // 488bcf | test ecx, ecx $sequence_2 = { 33c0 b906020000 f3aa 33c0 66898424d0060000 488d8424d2060000 488bf8 } // n = 7, score = 100 // 33c0 | js 0x835 // b906020000 | jae 0x82f // f3aa | dec eax // 33c0 | mov edi, ebx // 66898424d0060000 | dec esp // 488d8424d2060000 | lea esi, [0x12422] // 488bf8 | test ebx, ebx $sequence_3 = { 488bc2 e9???????? 493bec 0f84be000000 8b7500 33c0 f04d0fb1bcf120ba0100 } // n = 7, score = 100 // 488bc2 | imul ecx, ecx, 0 // e9???????? | // 493bec | dec eax // 0f84be000000 | mov edx, dword ptr [esp + 0x58] // 8b7500 | movsx ecx, byte ptr [edx + ecx] // 33c0 | dec eax // f04d0fb1bcf120ba0100 | arpl word ptr [esp + 0x44], cx $sequence_4 = { 4889842490000000 488b442470 0fb700 6689442432 488b442458 0fb74c2432 } // n = 6, score = 100 // 4889842490000000 | cmova ebp, eax // 488b442470 | inc esp // 0fb700 | mov dword ptr [esp + 0x48], ebp // 6689442432 | inc ecx // 488b442458 | lea eax, [ebp - 1] // 0fb74c2432 | movzx ecx, byte ptr [edx + eax*4 + 0x13fd2] $sequence_5 = { 4885c9 7430 53 4883ec20 488d0563810000 } // n = 5, score = 100 // 4885c9 | movzx esi, byte ptr [edx + eax*4 + 0x13fd3] // 7430 | mov ebx, ecx // 53 | mov edi, eax // 4883ec20 | xor edx, edx // 488d0563810000 | dec eax $sequence_6 = { eb19 488d1dec1e0100 eb10 488d1df31e0100 eb07 488d1dd21e0100 } // n = 6, score = 100 // eb19 | jmp 0x77 // 488d1dec1e0100 | dec eax // eb10 | mov eax, ebx // 488d1df31e0100 | dec ecx // eb07 | xchg dword ptr [edi + esi*8 + 0x1c0d0], eax // 488d1dd21e0100 | jne 0x73 $sequence_7 = { 4883ec20 e8???????? 488b05???????? 488d1da7710100 } // n = 4, score = 100 // 4883ec20 | dec eax // e8???????? | // 488b05???????? | // 488d1da7710100 | lea edx, [0xffffe52d] $sequence_8 = { e8???????? 89442460 33c9 e8???????? } // n = 4, score = 100 // e8???????? | // 89442460 | dec eax // 33c9 | lea eax, [0x14767] // e8???????? | $sequence_9 = { 85c0 750d 488bcb e8???????? e9???????? 4c8d2557230100 } // n = 6, score = 100 // 85c0 | lea ecx, [ebx + ebx*4] // 750d | dec eax // 488bcb | lea ecx, [eax + ecx*8] // e8???????? | // e9???????? | // 4c8d2557230100 | dec eax condition: 7 of them and filesize < 364544 }
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