Actor(s): DarkHotel
There is no description at this point.
rule win_jaku_auto { meta: author = "Felix Bilstein - yara-signator at cocacoding dot com" date = "2026-01-05" version = "1" description = "Detects win.jaku." 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.jaku" 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 = { 3945f8 0f94c0 eb02 32c0 } // n = 4, score = 1500 // 3945f8 | cmp dword ptr [ebp - 8], eax // 0f94c0 | sete al // eb02 | jmp 4 // 32c0 | xor al, al $sequence_1 = { 8bcf 83e107 d3eb 2bf9 895df4 83ff20 } // n = 6, score = 1500 // 8bcf | mov ecx, edi // 83e107 | and ecx, 7 // d3eb | shr ebx, cl // 2bf9 | sub edi, ecx // 895df4 | mov dword ptr [ebp - 0xc], ebx // 83ff20 | cmp edi, 0x20 $sequence_2 = { b83c800000 e8???????? 53 56 57 6a38 8d45c4 } // n = 7, score = 1500 // b83c800000 | mov eax, 0x803c // e8???????? | // 53 | push ebx // 56 | push esi // 57 | push edi // 6a38 | push 0x38 // 8d45c4 | lea eax, [ebp - 0x3c] $sequence_3 = { 33db 894618 895df4 c70601000000 e9???????? 8b4620 } // n = 6, score = 1500 // 33db | xor ebx, ebx // 894618 | mov dword ptr [esi + 0x18], eax // 895df4 | mov dword ptr [ebp - 0xc], ebx // c70601000000 | mov dword ptr [esi], 1 // e9???????? | // 8b4620 | mov eax, dword ptr [esi + 0x20] $sequence_4 = { 83c204 8bfa d3e7 8b4e14 6609beb8160000 } // n = 5, score = 1500 // 83c204 | add edx, 4 // 8bfa | mov edi, edx // d3e7 | shl edi, cl // 8b4e14 | mov ecx, dword ptr [esi + 0x14] // 6609beb8160000 | or word ptr [esi + 0x16b8], di $sequence_5 = { 7573 8bc3 83e00f 3c08 0f85a6000000 8b4624 83ef04 } // n = 7, score = 1500 // 7573 | jne 0x75 // 8bc3 | mov eax, ebx // 83e00f | and eax, 0xf // 3c08 | cmp al, 8 // 0f85a6000000 | jne 0xac // 8b4624 | mov eax, dword ptr [esi + 0x24] // 83ef04 | sub edi, 4 $sequence_6 = { 880c07 8b02 8a4df8 884c0701 8b0a 8bc6 2bc1 } // n = 7, score = 1500 // 880c07 | mov byte ptr [edi + eax], cl // 8b02 | mov eax, dword ptr [edx] // 8a4df8 | mov cl, byte ptr [ebp - 8] // 884c0701 | mov byte ptr [edi + eax + 1], cl // 8b0a | mov ecx, dword ptr [edx] // 8bc6 | mov eax, esi // 2bc1 | sub eax, ecx $sequence_7 = { 2bf8 83c410 85ff 7fd7 5b 56 } // n = 6, score = 1500 // 2bf8 | sub edi, eax // 83c410 | add esp, 0x10 // 85ff | test edi, edi // 7fd7 | jg 0xffffffd9 // 5b | pop ebx // 56 | push esi $sequence_8 = { 68???????? ff15???????? c3 b8???????? e8???????? 83ec2c } // n = 6, score = 800 // 68???????? | // ff15???????? | // c3 | ret // b8???????? | // e8???????? | // 83ec2c | sub esp, 0x2c $sequence_9 = { ff742408 e8???????? c20800 8bc1 } // n = 4, score = 600 // ff742408 | push dword ptr [esp + 8] // e8???????? | // c20800 | ret 8 // 8bc1 | mov eax, ecx $sequence_10 = { 53 68000000a0 6a03 53 } // n = 4, score = 500 // 53 | push ebx // 68000000a0 | push 0xa0000000 // 6a03 | push 3 // 53 | push ebx $sequence_11 = { 7507 b800308000 eb02 33c0 } // n = 4, score = 500 // 7507 | jne 9 // b800308000 | mov eax, 0x803000 // eb02 | jmp 4 // 33c0 | xor eax, eax $sequence_12 = { 7508 83c8ff e9???????? 8b839f830000 } // n = 4, score = 500 // 7508 | jne 0xa // 83c8ff | or eax, 0xffffffff // e9???????? | // 8b839f830000 | mov eax, dword ptr [ebx + 0x839f] $sequence_13 = { 6a01 03c3 68???????? 50 e8???????? 83c40c } // n = 6, score = 500 // 6a01 | push 1 // 03c3 | add eax, ebx // 68???????? | // 50 | push eax // e8???????? | // 83c40c | add esp, 0xc $sequence_14 = { 5b c3 55 8bec 833d????????00 53 56 } // n = 7, score = 500 // 5b | pop ebx // c3 | ret // 55 | push ebp // 8bec | mov ebp, esp // 833d????????00 | // 53 | push ebx // 56 | push esi $sequence_15 = { 55 56 57 6880020000 } // n = 4, score = 500 // 55 | push ebp // 56 | push esi // 57 | push edi // 6880020000 | push 0x280 $sequence_16 = { 75dd 57 e8???????? 59 } // n = 4, score = 500 // 75dd | jne 0xffffffdf // 57 | push edi // e8???????? | // 59 | pop ecx $sequence_17 = { 0245fd 3245fe 8a4dff d2c8 } // n = 4, score = 400 // 0245fd | add al, byte ptr [ebp - 3] // 3245fe | xor al, byte ptr [ebp - 2] // 8a4dff | mov cl, byte ptr [ebp - 1] // d2c8 | ror al, cl $sequence_18 = { 50 e8???????? 59 8b4e2c } // n = 4, score = 400 // 50 | push eax // e8???????? | // 59 | pop ecx // 8b4e2c | mov ecx, dword ptr [esi + 0x2c] $sequence_19 = { 85ff 897c240c 750c 5f 5e b801000000 5b } // n = 7, score = 400 // 85ff | test edi, edi // 897c240c | mov dword ptr [esp + 0xc], edi // 750c | jne 0xe // 5f | pop edi // 5e | pop esi // b801000000 | mov eax, 1 // 5b | pop ebx $sequence_20 = { 56 e8???????? 59 8b4620 } // n = 4, score = 400 // 56 | push esi // e8???????? | // 59 | pop ecx // 8b4620 | mov eax, dword ptr [esi + 0x20] $sequence_21 = { e8???????? 59 eb57 53 } // n = 4, score = 400 // e8???????? | // 59 | pop ecx // eb57 | jmp 0x59 // 53 | push ebx $sequence_22 = { 016c242c 8b44242c 5f 5e 5d } // n = 5, score = 400 // 016c242c | add dword ptr [esp + 0x2c], ebp // 8b44242c | mov eax, dword ptr [esp + 0x2c] // 5f | pop edi // 5e | pop esi // 5d | pop ebp $sequence_23 = { 50 894528 e8???????? 83c410 8b3d???????? 53 } // n = 6, score = 300 // 50 | push eax // 894528 | mov dword ptr [ebp + 0x28], eax // e8???????? | // 83c410 | add esp, 0x10 // 8b3d???????? | // 53 | push ebx $sequence_24 = { 53 53 53 6aff ff7528 bee9fd0000 } // n = 6, score = 300 // 53 | push ebx // 53 | push ebx // 53 | push ebx // 6aff | push -1 // ff7528 | push dword ptr [ebp + 0x28] // bee9fd0000 | mov esi, 0xfde9 $sequence_25 = { 56 57 8965f0 33ff 897dfc c645fc01 837d1c10 } // n = 7, score = 300 // 56 | push esi // 57 | push edi // 8965f0 | mov dword ptr [ebp - 0x10], esp // 33ff | xor edi, edi // 897dfc | mov dword ptr [ebp - 4], edi // c645fc01 | mov byte ptr [ebp - 4], 1 // 837d1c10 | cmp dword ptr [ebp + 0x1c], 0x10 $sequence_26 = { 8bbe9b830000 33db 8d4f01 43 } // n = 4, score = 300 // 8bbe9b830000 | mov edi, dword ptr [esi + 0x839b] // 33db | xor ebx, ebx // 8d4f01 | lea ecx, [edi + 1] // 43 | inc ebx $sequence_27 = { 6a00 8b9580faffff 837a3000 750b 8b8db4f9ffff 83c904 eb06 } // n = 7, score = 200 // 6a00 | push 0 // 8b9580faffff | mov edx, dword ptr [ebp - 0x580] // 837a3000 | cmp dword ptr [edx + 0x30], 0 // 750b | jne 0xd // 8b8db4f9ffff | mov ecx, dword ptr [ebp - 0x64c] // 83c904 | or ecx, 4 // eb06 | jmp 8 $sequence_28 = { 6a00 53 56 e8???????? 83c41c 8b55f8 8345f8ff } // n = 7, score = 200 // 6a00 | push 0 // 53 | push ebx // 56 | push esi // e8???????? | // 83c41c | add esp, 0x1c // 8b55f8 | mov edx, dword ptr [ebp - 8] // 8345f8ff | add dword ptr [ebp - 8], -1 condition: 7 of them and filesize < 2220032 }
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