Actor(s): Comment Crew
There is no description at this point.
rule win_biscuit_auto { meta: author = "Felix Bilstein - yara-signator at cocacoding dot com" date = "2023-03-28" version = "1" description = "Detects win.biscuit." 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.biscuit" malpedia_rule_date = "20230328" malpedia_hash = "9d2d75cef573c1c2d861f5197df8f563b05a305d" malpedia_version = "20230407" 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 = { c745fc00000002 8bf0 b903000000 bf???????? 33c0 f3a6 7507 } // n = 7, score = 100 // c745fc00000002 | mov dword ptr [ebp - 4], 0x2000000 // 8bf0 | mov esi, eax // b903000000 | mov ecx, 3 // bf???????? | // 33c0 | xor eax, eax // f3a6 | repe cmpsb byte ptr [esi], byte ptr es:[edi] // 7507 | jne 9 $sequence_1 = { 8bfb 83c9ff 33c0 83c418 } // n = 4, score = 100 // 8bfb | mov edi, ebx // 83c9ff | or ecx, 0xffffffff // 33c0 | xor eax, eax // 83c418 | add esp, 0x18 $sequence_2 = { e8???????? 83c404 8945f0 b919000000 33c0 8b7df0 f3ab } // n = 7, score = 100 // e8???????? | // 83c404 | add esp, 4 // 8945f0 | mov dword ptr [ebp - 0x10], eax // b919000000 | mov ecx, 0x19 // 33c0 | xor eax, eax // 8b7df0 | mov edi, dword ptr [ebp - 0x10] // f3ab | rep stosd dword ptr es:[edi], eax $sequence_3 = { 8d8c2410050000 51 8b8c2484020000 52 50 8d94241c030000 } // n = 6, score = 100 // 8d8c2410050000 | lea ecx, [esp + 0x510] // 51 | push ecx // 8b8c2484020000 | mov ecx, dword ptr [esp + 0x284] // 52 | push edx // 50 | push eax // 8d94241c030000 | lea edx, [esp + 0x31c] $sequence_4 = { 8975f0 8975e4 8975fc 8975e8 e8???????? } // n = 5, score = 100 // 8975f0 | mov dword ptr [ebp - 0x10], esi // 8975e4 | mov dword ptr [ebp - 0x1c], esi // 8975fc | mov dword ptr [ebp - 4], esi // 8975e8 | mov dword ptr [ebp - 0x18], esi // e8???????? | $sequence_5 = { 0f8547040000 6a02 68???????? b9???????? } // n = 4, score = 100 // 0f8547040000 | jne 0x44d // 6a02 | push 2 // 68???????? | // b9???????? | $sequence_6 = { 898d04b8ffff 8b9504b8ffff 52 e8???????? 83c404 } // n = 5, score = 100 // 898d04b8ffff | mov dword ptr [ebp - 0x47fc], ecx // 8b9504b8ffff | mov edx, dword ptr [ebp - 0x47fc] // 52 | push edx // e8???????? | // 83c404 | add esp, 4 $sequence_7 = { 89956c9fffff 8b856c9fffff 8a08 80e901 8b956c9fffff 880a } // n = 6, score = 100 // 89956c9fffff | mov dword ptr [ebp - 0x6094], edx // 8b856c9fffff | mov eax, dword ptr [ebp - 0x6094] // 8a08 | mov cl, byte ptr [eax] // 80e901 | sub cl, 1 // 8b956c9fffff | mov edx, dword ptr [ebp - 0x6094] // 880a | mov byte ptr [edx], cl $sequence_8 = { 33c0 8a42ff 85c0 7410 8b4de4 33d2 } // n = 6, score = 100 // 33c0 | xor eax, eax // 8a42ff | mov al, byte ptr [edx - 1] // 85c0 | test eax, eax // 7410 | je 0x12 // 8b4de4 | mov ecx, dword ptr [ebp - 0x1c] // 33d2 | xor edx, edx $sequence_9 = { 7413 8b8d30fdffff 33d2 8a51ff 81faff000000 752f 8b8538fdffff } // n = 7, score = 100 // 7413 | je 0x15 // 8b8d30fdffff | mov ecx, dword ptr [ebp - 0x2d0] // 33d2 | xor edx, edx // 8a51ff | mov dl, byte ptr [ecx - 1] // 81faff000000 | cmp edx, 0xff // 752f | jne 0x31 // 8b8538fdffff | mov eax, dword ptr [ebp - 0x2c8] condition: 7 of them and filesize < 180224 }
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