Actor(s): Kimsuky
There is no description at this point.
rule win_grease_auto { meta: author = "Felix Bilstein - yara-signator at cocacoding dot com" date = "2023-07-11" version = "1" description = "Detects win.grease." 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.grease" malpedia_rule_date = "20230705" malpedia_hash = "42d0574f4405bd7d2b154d321d345acb18834a41" malpedia_version = "20230715" 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 = { 52 50 683f000f00 50 50 50 } // n = 6, score = 400 // 52 | push edx // 50 | push eax // 683f000f00 | push 0xf003f // 50 | push eax // 50 | push eax // 50 | push eax $sequence_1 = { 488b4c2460 ff15???????? b801000000 488b8c2480020000 4833cc e8???????? } // n = 6, score = 300 // 488b4c2460 | xor eax, eax // ff15???????? | // b801000000 | dec eax // 488b8c2480020000 | mov edx, ebx // 4833cc | mov dword ptr [esp + 0x28], 4 // e8???????? | $sequence_2 = { 488b4c2460 48897c2440 488d442450 4889442438 48897c2430 } // n = 5, score = 300 // 488b4c2460 | dec eax // 48897c2440 | mov ecx, dword ptr [esp + 0x60] // 488d442450 | dec eax // 4889442438 | mov ecx, dword ptr [esp + 0x60] // 48897c2430 | dec eax $sequence_3 = { 4533c0 c74424283f000f00 897c2420 ff15???????? 85c0 } // n = 5, score = 300 // 4533c0 | mov dword ptr [esp + 0x28], 4 // c74424283f000f00 | dec eax // 897c2420 | mov dword ptr [esp + 0x20], eax // ff15???????? | // 85c0 | dec eax $sequence_4 = { 4053 4881ec90020000 488b05???????? 4833c4 4889842480020000 488d4c2472 } // n = 6, score = 300 // 4053 | mov dword ptr [esp + 0x30], edi // 4881ec90020000 | inc ebp // 488b05???????? | // 4833c4 | xor eax, eax // 4889842480020000 | inc ebp // 488d4c2472 | xor ecx, ecx $sequence_5 = { 488bd3 c744242804000000 4889442420 ff15???????? 488b4c2450 ff15???????? } // n = 6, score = 300 // 488bd3 | mov dword ptr [esp + 0x40], edi // c744242804000000 | dec eax // 4889442420 | lea eax, [esp + 0x50] // ff15???????? | // 488b4c2450 | dec eax // ff15???????? | $sequence_6 = { 48897c2440 4889442438 48897c2430 4533c0 c74424283f000f00 } // n = 5, score = 300 // 48897c2440 | mov dword ptr [esp + 0x38], eax // 4889442438 | dec eax // 48897c2430 | mov dword ptr [esp + 0x30], edi // 4533c0 | dec eax // c74424283f000f00 | mov edx, ebx $sequence_7 = { 7534 488b4c2450 488d442458 41b904000000 4533c0 488bd3 c744242804000000 } // n = 7, score = 300 // 7534 | mov ecx, dword ptr [esp + 0x50] // 488b4c2450 | dec eax // 488d442458 | mov dword ptr [esp + 0x40], edi // 41b904000000 | dec eax // 4533c0 | mov dword ptr [esp + 0x38], eax // 488bd3 | dec eax // c744242804000000 | mov dword ptr [esp + 0x30], edi $sequence_8 = { 48c7c102000080 c74424281f000200 895c2420 ff15???????? 85c0 0f85e7000000 488b4c2460 } // n = 7, score = 300 // 48c7c102000080 | dec eax // c74424281f000200 | mov ecx, 0x80000002 // 895c2420 | mov dword ptr [esp + 0x28], 0x2001f // ff15???????? | // 85c0 | mov dword ptr [esp + 0x20], ebx // 0f85e7000000 | test eax, eax // 488b4c2460 | jne 0xed $sequence_9 = { c684342807000065 e9???????? c684342807000075 e9???????? c68434280700006e e9???????? } // n = 6, score = 200 // c684342807000065 | mov byte ptr [esp + esi + 0x728], 0x65 // e9???????? | // c684342807000075 | mov byte ptr [esp + esi + 0x728], 0x75 // e9???????? | // c68434280700006e | mov byte ptr [esp + esi + 0x728], 0x6e // e9???????? | $sequence_10 = { 8b44240c 8b35???????? 50 ffd6 8d4c2418 68???????? } // n = 6, score = 200 // 8b44240c | mov eax, dword ptr [esp + 0xc] // 8b35???????? | // 50 | push eax // ffd6 | call esi // 8d4c2418 | lea ecx, [esp + 0x18] // 68???????? | $sequence_11 = { c1f805 83e11f 8b048560e44000 8d04c8 8b0b 8908 } // n = 6, score = 200 // c1f805 | sar eax, 5 // 83e11f | and ecx, 0x1f // 8b048560e44000 | mov eax, dword ptr [eax*4 + 0x40e460] // 8d04c8 | lea eax, [eax + ecx*8] // 8b0b | mov ecx, dword ptr [ebx] // 8908 | mov dword ptr [eax], ecx $sequence_12 = { c684341c0400002f eb1c c684341c0400003f eb12 c684341c0400002e eb08 } // n = 6, score = 200 // c684341c0400002f | mov byte ptr [esp + esi + 0x41c], 0x2f // eb1c | jmp 0x1e // c684341c0400003f | mov byte ptr [esp + esi + 0x41c], 0x3f // eb12 | jmp 0x14 // c684341c0400002e | mov byte ptr [esp + esi + 0x41c], 0x2e // eb08 | jmp 0xa $sequence_13 = { ffd5 8b4c2410 8b35???????? 51 } // n = 4, score = 200 // ffd5 | call ebp // 8b4c2410 | mov ecx, dword ptr [esp + 0x10] // 8b35???????? | // 51 | push ecx $sequence_14 = { f3a5 e8???????? 8d84243c040000 83c40c 8d5001 8bff } // n = 6, score = 200 // f3a5 | rep movsd dword ptr es:[edi], dword ptr [esi] // e8???????? | // 8d84243c040000 | lea eax, [esp + 0x43c] // 83c40c | add esp, 0xc // 8d5001 | lea edx, [eax + 1] // 8bff | mov edi, edi $sequence_15 = { c68434100100003d e9???????? c68434100100005f e9???????? c68434100100003a e9???????? } // n = 6, score = 200 // c68434100100003d | mov byte ptr [esp + esi + 0x110], 0x3d // e9???????? | // c68434100100005f | mov byte ptr [esp + esi + 0x110], 0x5f // e9???????? | // c68434100100003a | mov byte ptr [esp + esi + 0x110], 0x3a // e9???????? | $sequence_16 = { eb58 c68434100100003c eb4e c684341001000028 } // n = 4, score = 200 // eb58 | jmp 0x5a // c68434100100003c | mov byte ptr [esp + esi + 0x110], 0x3c // eb4e | jmp 0x50 // c684341001000028 | mov byte ptr [esp + esi + 0x110], 0x28 $sequence_17 = { 85c0 75f4 33c9 85f6 } // n = 4, score = 200 // 85c0 | test eax, eax // 75f4 | jne 0xfffffff6 // 33c9 | xor ecx, ecx // 85f6 | test esi, esi $sequence_18 = { c644340c64 e9???????? c644340c70 e9???????? c644340c73 e9???????? c644340c74 } // n = 7, score = 200 // c644340c64 | mov byte ptr [esp + esi + 0xc], 0x64 // e9???????? | // c644340c70 | mov byte ptr [esp + esi + 0xc], 0x70 // e9???????? | // c644340c73 | mov byte ptr [esp + esi + 0xc], 0x73 // e9???????? | // c644340c74 | mov byte ptr [esp + esi + 0xc], 0x74 $sequence_19 = { 50 e8???????? 83c40c 6a00 8d8c240c010000 51 ffd6 } // n = 7, score = 200 // 50 | push eax // e8???????? | // 83c40c | add esp, 0xc // 6a00 | push 0 // 8d8c240c010000 | lea ecx, [esp + 0x10c] // 51 | push ecx // ffd6 | call esi $sequence_20 = { 83c001 3ad3 75f7 2bc1 53 66899c442c010000 } // n = 6, score = 200 // 83c001 | add eax, 1 // 3ad3 | cmp dl, bl // 75f7 | jne 0xfffffff9 // 2bc1 | sub eax, ecx // 53 | push ebx // 66899c442c010000 | mov word ptr [esp + eax*2 + 0x12c], bx $sequence_21 = { 8d4c241c 51 53 68???????? 52 c744243804000000 } // n = 6, score = 200 // 8d4c241c | lea ecx, [esp + 0x1c] // 51 | push ecx // 53 | push ebx // 68???????? | // 52 | push edx // c744243804000000 | mov dword ptr [esp + 0x38], 4 $sequence_22 = { 83c001 50 8d542430 52 53 53 ff15???????? } // n = 7, score = 200 // 83c001 | add eax, 1 // 50 | push eax // 8d542430 | lea edx, [esp + 0x30] // 52 | push edx // 53 | push ebx // 53 | push ebx // ff15???????? | condition: 7 of them and filesize < 278528 }
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