C2 framework.
rule win_nighthawk_auto { meta: author = "Felix Bilstein - yara-signator at cocacoding dot com" date = "2023-12-06" version = "1" description = "Detects win.nighthawk." 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.nighthawk" malpedia_rule_date = "20231130" malpedia_hash = "fc8a0e9f343f6d6ded9e7df1a64dac0cc68d7351" malpedia_version = "20230808" 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 = { 8983a8000000 4c397d0f 720f 488b4df7 4885c9 7406 e8???????? } // n = 7, score = 100 // 8983a8000000 | inc esi // 4c397d0f | mov byte ptr [ecx + esi*8 + 0x3e], bl // 720f | dec eax // 488b4df7 | cmp edx, esi // 4885c9 | dec ecx // 7406 | mov edx, ebx // e8???????? | $sequence_1 = { ff15???????? 48897b48 48837b3808 720e 488b4b20 4885c9 7405 } // n = 7, score = 100 // ff15???????? | // 48897b48 | je 0xe3d // 48837b3808 | movsx edx, byte ptr [eax] // 720e | inc ecx // 488b4b20 | add edx, edi // 4885c9 | dec eax // 7405 | lea ecx, [eax + 1] $sequence_2 = { 740d 0f104030 448d7701 0f11442420 498d4f30 ff15???????? 4585f6 } // n = 7, score = 100 // 740d | dec eax // 0f104030 | lea eax, [0x3a954] // 448d7701 | dec eax // 0f11442420 | lea edx, [edx + 2] // 498d4f30 | test ax, ax // ff15???????? | // 4585f6 | jne 0x1e37 $sequence_3 = { 4c8bd2 488d354b95f5ff 4183e20f 488bfa 492bfa 488bda 4c8bc1 } // n = 7, score = 100 // 4c8bd2 | mov edx, 4 // 488d354b95f5ff | dec eax // 4183e20f | mov ecx, ebx // 488bfa | dec eax // 492bfa | mov ecx, edi // 488bda | dec esp // 4c8bc1 | mov eax, eax $sequence_4 = { 7419 e8???????? 488b5310 41b801000000 488bc8 e8???????? eba5 } // n = 7, score = 100 // 7419 | mov eax, 4 // e8???????? | // 488b5310 | dec ecx // 41b801000000 | mov ecx, ebp // 488bc8 | dec ecx // e8???????? | // eba5 | sub ebp, esp $sequence_5 = { ff15???????? 85c0 0f844a040000 448b4510 4c897588 4c897598 458d7e0f } // n = 7, score = 100 // ff15???????? | // 85c0 | mov esi, dword ptr [esi] // 0f844a040000 | jmp 0xb33 // 448b4510 | dec ecx // 4c897588 | mov esi, esi // 4c897598 | je 0xb45 // 458d7e0f | dec eax $sequence_6 = { 8b02 418901 890a e9???????? 418b08 418b03 418900 } // n = 7, score = 100 // 8b02 | movzx ecx, byte ptr [edx + edx] // 418901 | lea eax, [edx + 1] // 890a | inc esi // e9???????? | // 418b08 | movzx eax, byte ptr [eax + edx] // 418b03 | lea eax, [edx + 2] // 418900 | dec ecx $sequence_7 = { 4903ca 4b890c01 eb34 6683f803 7509 4923ce 46011401 } // n = 7, score = 100 // 4903ca | mov dword ptr [edi + 0xe8], ebp // 4b890c01 | dec esp // eb34 | mov dword ptr [edi + 0xf8], ebp // 6683f803 | dec eax // 7509 | mov dword ptr [edi + 0x100], ebx // 4923ce | inc sp // 46011401 | mov dword ptr [edi + 0xe8], ebp $sequence_8 = { 488d542470 488d4d20 e8???????? 488bd0 488d4d40 e8???????? 90 } // n = 7, score = 100 // 488d542470 | mov ebx, eax // 488d4d20 | inc esp // e8???????? | // 488bd0 | lea eax, [edx + 0x20] // 488d4d40 | dec esp // e8???????? | // 90 | mov eax, ebx $sequence_9 = { 4c894c2448 4c89642440 4c89642438 4489642430 48894c2428 4889442420 4533c9 } // n = 7, score = 100 // 4c894c2448 | dec eax // 4c89642440 | test ecx, ecx // 4c89642438 | je 0x12d3 // 4489642430 | nop // 48894c2428 | dec esp // 4889442420 | mov dword ptr [esp + 0x20], ebp // 4533c9 | dec eax condition: 7 of them and filesize < 1949696 }
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