Actor(s): Hellsing
There is no description at this point.
rule win_newcore_rat_auto { meta: author = "Felix Bilstein - yara-signator at cocacoding dot com" date = "2026-01-05" version = "1" description = "Detects win.newcore_rat." 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.newcore_rat" 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 = { 8b883c200000 52 51 c744241000000000 ff15???????? f7d8 1bc0 } // n = 7, score = 100 // 8b883c200000 | mov ecx, dword ptr [eax + 0x203c] // 52 | push edx // 51 | push ecx // c744241000000000 | mov dword ptr [esp + 0x10], 0 // ff15???????? | // f7d8 | neg eax // 1bc0 | sbb eax, eax $sequence_1 = { 51 57 6a01 53 52 55 ff15???????? } // n = 7, score = 100 // 51 | push ecx // 57 | push edi // 6a01 | push 1 // 53 | push ebx // 52 | push edx // 55 | push ebp // ff15???????? | $sequence_2 = { c686c800000043 c6864b01000043 c7466878920310 6a0d e8???????? 59 8365fc00 } // n = 7, score = 100 // c686c800000043 | mov byte ptr [esi + 0xc8], 0x43 // c6864b01000043 | mov byte ptr [esi + 0x14b], 0x43 // c7466878920310 | mov dword ptr [esi + 0x68], 0x10039278 // 6a0d | push 0xd // e8???????? | // 59 | pop ecx // 8365fc00 | and dword ptr [ebp - 4], 0 $sequence_3 = { 0f8788000000 0fb69028720010 ff249508720010 33c0 83c40c c3 8b4644 } // n = 7, score = 100 // 0f8788000000 | ja 0x8e // 0fb69028720010 | movzx edx, byte ptr [eax + 0x10007228] // ff249508720010 | jmp dword ptr [edx*4 + 0x10007208] // 33c0 | xor eax, eax // 83c40c | add esp, 0xc // c3 | ret // 8b4644 | mov eax, dword ptr [esi + 0x44] $sequence_4 = { 57 8b78f4 894dfc 85db } // n = 4, score = 100 // 57 | push edi // 8b78f4 | mov edi, dword ptr [eax - 0xc] // 894dfc | mov dword ptr [ebp - 4], ecx // 85db | test ebx, ebx $sequence_5 = { 0430 0fb64c2426 8844242f 8bc1 c1e804 83f809 } // n = 6, score = 100 // 0430 | add al, 0x30 // 0fb64c2426 | movzx ecx, byte ptr [esp + 0x26] // 8844242f | mov byte ptr [esp + 0x2f], al // 8bc1 | mov eax, ecx // c1e804 | shr eax, 4 // 83f809 | cmp eax, 9 $sequence_6 = { 8984242c040000 8b842434040000 53 55 56 57 8bf1 } // n = 7, score = 100 // 8984242c040000 | mov dword ptr [esp + 0x42c], eax // 8b842434040000 | mov eax, dword ptr [esp + 0x434] // 53 | push ebx // 55 | push ebp // 56 | push esi // 57 | push edi // 8bf1 | mov esi, ecx $sequence_7 = { 81ec54020000 a1???????? 33c4 8984244c020000 8b842458020000 55 } // n = 6, score = 100 // 81ec54020000 | sub esp, 0x254 // a1???????? | // 33c4 | xor eax, esp // 8984244c020000 | mov dword ptr [esp + 0x24c], eax // 8b842458020000 | mov eax, dword ptr [esp + 0x258] // 55 | push ebp $sequence_8 = { b903000000 668994249c000000 668984249e000000 66898c24a0000000 ba01000000 66899424a2000000 b809000000 } // n = 7, score = 100 // b903000000 | mov ecx, 3 // 668994249c000000 | mov word ptr [esp + 0x9c], dx // 668984249e000000 | mov word ptr [esp + 0x9e], ax // 66898c24a0000000 | mov word ptr [esp + 0xa0], cx // ba01000000 | mov edx, 1 // 66899424a2000000 | mov word ptr [esp + 0xa2], dx // b809000000 | mov eax, 9 $sequence_9 = { e9???????? 8b442410 6a04 56 50 8bde c744242400000000 } // n = 7, score = 100 // e9???????? | // 8b442410 | mov eax, dword ptr [esp + 0x10] // 6a04 | push 4 // 56 | push esi // 50 | push eax // 8bde | mov ebx, esi // c744242400000000 | mov dword ptr [esp + 0x24], 0 condition: 7 of them and filesize < 581632 }
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