Actor(s): SNOWGLOBE
There is no description at this point.
rule win_evilbunny_auto { meta: author = "Felix Bilstein - yara-signator at cocacoding dot com" date = "2026-01-05" version = "1" description = "Detects win.evilbunny." 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.evilbunny" 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 = { eb37 6a00 8b4df4 2b4d0c 51 8b55fc 8b4218 } // n = 7, score = 200 // eb37 | jmp 0x39 // 6a00 | push 0 // 8b4df4 | mov ecx, dword ptr [ebp - 0xc] // 2b4d0c | sub ecx, dword ptr [ebp + 0xc] // 51 | push ecx // 8b55fc | mov edx, dword ptr [ebp - 4] // 8b4218 | mov eax, dword ptr [edx + 0x18] $sequence_1 = { 2b45e4 1b55e8 8945a0 8955a4 eb0e c745a000000000 c745a400000000 } // n = 7, score = 200 // 2b45e4 | sub eax, dword ptr [ebp - 0x1c] // 1b55e8 | sbb edx, dword ptr [ebp - 0x18] // 8945a0 | mov dword ptr [ebp - 0x60], eax // 8955a4 | mov dword ptr [ebp - 0x5c], edx // eb0e | jmp 0x10 // c745a000000000 | mov dword ptr [ebp - 0x60], 0 // c745a400000000 | mov dword ptr [ebp - 0x5c], 0 $sequence_2 = { 8b55f8 8b4218 8b550c 891401 8b450c 0fb64805 83e103 } // n = 7, score = 200 // 8b55f8 | mov edx, dword ptr [ebp - 8] // 8b4218 | mov eax, dword ptr [edx + 0x18] // 8b550c | mov edx, dword ptr [ebp + 0xc] // 891401 | mov dword ptr [ecx + eax], edx // 8b450c | mov eax, dword ptr [ebp + 0xc] // 0fb64805 | movzx ecx, byte ptr [eax + 5] // 83e103 | and ecx, 3 $sequence_3 = { 8b5518 c1e20e 0bc2 50 8b4508 50 e8???????? } // n = 7, score = 200 // 8b5518 | mov edx, dword ptr [ebp + 0x18] // c1e20e | shl edx, 0xe // 0bc2 | or eax, edx // 50 | push eax // 8b4508 | mov eax, dword ptr [ebp + 8] // 50 | push eax // e8???????? | $sequence_4 = { 8d8c3a4b661aa8 894df8 8b95ccfeffff c1ea02 8b85ccfeffff c1e01e 0bd0 } // n = 7, score = 200 // 8d8c3a4b661aa8 | lea ecx, [edx + edi - 0x57e599b5] // 894df8 | mov dword ptr [ebp - 8], ecx // 8b95ccfeffff | mov edx, dword ptr [ebp - 0x134] // c1ea02 | shr edx, 2 // 8b85ccfeffff | mov eax, dword ptr [ebp - 0x134] // c1e01e | shl eax, 0x1e // 0bd0 | or edx, eax $sequence_5 = { 55 8bec 51 8b4508 8b4824 034d0c 894dfc } // n = 7, score = 200 // 55 | push ebp // 8bec | mov ebp, esp // 51 | push ecx // 8b4508 | mov eax, dword ptr [ebp + 8] // 8b4824 | mov ecx, dword ptr [eax + 0x24] // 034d0c | add ecx, dword ptr [ebp + 0xc] // 894dfc | mov dword ptr [ebp - 4], ecx $sequence_6 = { e8???????? 8b55f8 c782060c000001000000 33c0 52 8bcd 50 } // n = 7, score = 200 // e8???????? | // 8b55f8 | mov edx, dword ptr [ebp - 8] // c782060c000001000000 | mov dword ptr [edx + 0xc06], 1 // 33c0 | xor eax, eax // 52 | push edx // 8bcd | mov ecx, ebp // 50 | push eax $sequence_7 = { e8???????? 8b858cfeffff 52 8bcd 50 8d1540f91000 e8???????? } // n = 7, score = 200 // e8???????? | // 8b858cfeffff | mov eax, dword ptr [ebp - 0x174] // 52 | push edx // 8bcd | mov ecx, ebp // 50 | push eax // 8d1540f91000 | lea edx, [0x10f940] // e8???????? | $sequence_8 = { e8???????? 83c408 8b4dfc 51 8b95e4fdffff 52 8d85e8fdffff } // n = 7, score = 200 // e8???????? | // 83c408 | add esp, 8 // 8b4dfc | mov ecx, dword ptr [ebp - 4] // 51 | push ecx // 8b95e4fdffff | mov edx, dword ptr [ebp - 0x21c] // 52 | push edx // 8d85e8fdffff | lea eax, [ebp - 0x218] $sequence_9 = { 8b5508 8b4238 89413c 8b4d08 8a5510 885136 b801000000 } // n = 7, score = 200 // 8b5508 | mov edx, dword ptr [ebp + 8] // 8b4238 | mov eax, dword ptr [edx + 0x38] // 89413c | mov dword ptr [ecx + 0x3c], eax // 8b4d08 | mov ecx, dword ptr [ebp + 8] // 8a5510 | mov dl, byte ptr [ebp + 0x10] // 885136 | mov byte ptr [ecx + 0x36], dl // b801000000 | mov eax, 1 condition: 7 of them and filesize < 1695744 }
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