Actor(s): Lazarus Group
There is no description at this point.
rule win_wannacryptor_auto { meta: author = "Felix Bilstein - yara-signator at cocacoding dot com" date = "2023-01-25" version = "1" description = "Detects win.wannacryptor." 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.wannacryptor" malpedia_rule_date = "20230124" malpedia_hash = "2ee0eebba83dce3d019a90519f2f972c0fcf9686" malpedia_version = "20230125" 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 = { 8b74243c 8bca c1e917 c1e81e } // n = 4, score = 600 // 8b74243c | mov esi, dword ptr [esp + 0x3c] // 8bca | mov ecx, edx // c1e917 | shr ecx, 0x17 // c1e81e | shr eax, 0x1e $sequence_1 = { 8bf0 8975dc 83feff 750a 50 } // n = 5, score = 600 // 8bf0 | mov esi, eax // 8975dc | mov dword ptr [ebp - 0x24], esi // 83feff | cmp esi, -1 // 750a | jne 0xc // 50 | push eax $sequence_2 = { a1???????? 8b0d???????? 8944240c 8d44240c } // n = 4, score = 600 // a1???????? | // 8b0d???????? | // 8944240c | mov dword ptr [esp + 0xc], eax // 8d44240c | lea eax, [esp + 0xc] $sequence_3 = { 5b 59 c20c00 8bce e8???????? 84c0 } // n = 6, score = 600 // 5b | pop ebx // 59 | pop ecx // c20c00 | ret 0xc // 8bce | mov ecx, esi // e8???????? | // 84c0 | test al, al $sequence_4 = { 895c242c ff15???????? 85c0 7e7e 8d4c243c 51 } // n = 6, score = 600 // 895c242c | mov dword ptr [esp + 0x2c], ebx // ff15???????? | // 85c0 | test eax, eax // 7e7e | jle 0x80 // 8d4c243c | lea ecx, [esp + 0x3c] // 51 | push ecx $sequence_5 = { 83fa01 0f850f010000 38564b 7526 8b4644 } // n = 5, score = 600 // 83fa01 | cmp edx, 1 // 0f850f010000 | jne 0x115 // 38564b | cmp byte ptr [esi + 0x4b], dl // 7526 | jne 0x28 // 8b4644 | mov eax, dword ptr [esi + 0x44] $sequence_6 = { 0f8c8a000000 8b4d04 8b5500 8d442414 6a04 50 } // n = 6, score = 600 // 0f8c8a000000 | jl 0x90 // 8b4d04 | mov ecx, dword ptr [ebp + 4] // 8b5500 | mov edx, dword ptr [ebp] // 8d442414 | lea eax, [esp + 0x14] // 6a04 | push 4 // 50 | push eax $sequence_7 = { 83ec10 56 8bf1 57 8b7c241c 8b4670 85c0 } // n = 7, score = 600 // 83ec10 | sub esp, 0x10 // 56 | push esi // 8bf1 | mov esi, ecx // 57 | push edi // 8b7c241c | mov edi, dword ptr [esp + 0x1c] // 8b4670 | mov eax, dword ptr [esi + 0x70] // 85c0 | test eax, eax $sequence_8 = { 8b4678 8d7e44 85c0 755f 8b17 } // n = 5, score = 600 // 8b4678 | mov eax, dword ptr [esi + 0x78] // 8d7e44 | lea edi, [esi + 0x44] // 85c0 | test eax, eax // 755f | jne 0x61 // 8b17 | mov edx, dword ptr [edi] $sequence_9 = { 7406 09bd08010000 8b4c2454 8b542458 898d24010000 8b4c244c } // n = 6, score = 600 // 7406 | je 8 // 09bd08010000 | or dword ptr [ebp + 0x108], edi // 8b4c2454 | mov ecx, dword ptr [esp + 0x54] // 8b542458 | mov edx, dword ptr [esp + 0x58] // 898d24010000 | mov dword ptr [ebp + 0x124], ecx // 8b4c244c | mov ecx, dword ptr [esp + 0x4c] condition: 7 of them and filesize < 540672 }
If your designated proposal does not fit in any other category, feel free to write a free-text in the comment field below.
Please propose all changes regarding references on the Malpedia library page
Your suggestion will be reviewed before being published. Thank you for contributing!
YYYY-MM-DD
YYYY-MM
YYYY