Actor(s): Oktropys
Ransomware
rule win_aurora_auto { meta: author = "Felix Bilstein - yara-signator at cocacoding dot com" date = "2026-01-05" version = "1" description = "Detects win.aurora." 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.aurora" malpedia_rule_date = "20260105" malpedia_hash = "19b79e7cab4eaf532122e5b45a77dd8f6bb5cc79" malpedia_version = "20251219" 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 = { 52 8d4dc0 e8???????? 68???????? c645fc01 e8???????? } // n = 6, score = 300 // 52 | push edx // 8d4dc0 | lea ecx, [ebp - 0x40] // e8???????? | // 68???????? | // c645fc01 | mov byte ptr [ebp - 4], 1 // e8???????? | $sequence_1 = { 6a1f 68???????? c745d40f000000 c745d000000000 c645c000 e8???????? c645fc01 } // n = 7, score = 300 // 6a1f | push 0x1f // 68???????? | // c745d40f000000 | mov dword ptr [ebp - 0x2c], 0xf // c745d000000000 | mov dword ptr [ebp - 0x30], 0 // c645c000 | mov byte ptr [ebp - 0x40], 0 // e8???????? | // c645fc01 | mov byte ptr [ebp - 4], 1 $sequence_2 = { 0f8259ffffff 8d4de4 e8???????? 8bc6 8b4df4 64890d00000000 59 } // n = 7, score = 300 // 0f8259ffffff | jb 0xffffff5f // 8d4de4 | lea ecx, [ebp - 0x1c] // e8???????? | // 8bc6 | mov eax, esi // 8b4df4 | mov ecx, dword ptr [ebp - 0xc] // 64890d00000000 | mov dword ptr fs:[0], ecx // 59 | pop ecx $sequence_3 = { 75f9 2bca 51 53 8d4dd0 e8???????? } // n = 6, score = 300 // 75f9 | jne 0xfffffffb // 2bca | sub ecx, edx // 51 | push ecx // 53 | push ebx // 8d4dd0 | lea ecx, [ebp - 0x30] // e8???????? | $sequence_4 = { 0f45c2 50 e8???????? 8bfb } // n = 4, score = 300 // 0f45c2 | cmovne eax, edx // 50 | push eax // e8???????? | // 8bfb | mov edi, ebx $sequence_5 = { 68???????? 8d8de4f1ffff c785f8f1ffff0f000000 c785f4f1ffff00000000 c685e4f1ffff00 e8???????? } // n = 6, score = 300 // 68???????? | // 8d8de4f1ffff | lea ecx, [ebp - 0xe1c] // c785f8f1ffff0f000000 | mov dword ptr [ebp - 0xe08], 0xf // c785f4f1ffff00000000 | mov dword ptr [ebp - 0xe0c], 0 // c685e4f1ffff00 | mov byte ptr [ebp - 0xe1c], 0 // e8???????? | $sequence_6 = { c785b8efffff0f000000 c785b4efffff00000000 c685a4efffff00 e8???????? 8d8dbcefffff } // n = 5, score = 300 // c785b8efffff0f000000 | mov dword ptr [ebp - 0x1048], 0xf // c785b4efffff00000000 | mov dword ptr [ebp - 0x104c], 0 // c685a4efffff00 | mov byte ptr [ebp - 0x105c], 0 // e8???????? | // 8d8dbcefffff | lea ecx, [ebp - 0x1044] $sequence_7 = { 0f8483000000 c1e706 03f8 83c106 894ddc 7869 8bc7 } // n = 7, score = 300 // 0f8483000000 | je 0x89 // c1e706 | shl edi, 6 // 03f8 | add edi, eax // 83c106 | add ecx, 6 // 894ddc | mov dword ptr [ebp - 0x24], ecx // 7869 | js 0x6b // 8bc7 | mov eax, edi $sequence_8 = { 68???????? 8d8d24f1ffff c78538f1ffff0f000000 c78534f1ffff00000000 } // n = 4, score = 300 // 68???????? | // 8d8d24f1ffff | lea ecx, [ebp - 0xedc] // c78538f1ffff0f000000 | mov dword ptr [ebp - 0xec8], 0xf // c78534f1ffff00000000 | mov dword ptr [ebp - 0xecc], 0 $sequence_9 = { a1???????? 33c5 50 8d45f4 64a300000000 c745ec00000000 83ec18 } // n = 7, score = 300 // a1???????? | // 33c5 | xor eax, ebp // 50 | push eax // 8d45f4 | lea eax, [ebp - 0xc] // 64a300000000 | mov dword ptr fs:[0], eax // c745ec00000000 | mov dword ptr [ebp - 0x14], 0 // 83ec18 | sub esp, 0x18 condition: 7 of them and filesize < 827392 }
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