Actor(s): Comment Crew
There is no description at this point.
rule win_webc2_kt3_auto { meta: author = "Felix Bilstein - yara-signator at cocacoding dot com" date = "2026-01-05" version = "1" description = "Detects win.webc2_kt3." 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.webc2_kt3" 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 = { 83c1ff 51 8b4df4 51 8b15???????? 52 } // n = 6, score = 100 // 83c1ff | add ecx, -1 // 51 | push ecx // 8b4df4 | mov ecx, dword ptr [ebp - 0xc] // 51 | push ecx // 8b15???????? | // 52 | push edx $sequence_1 = { 51 e8???????? 83c404 8985e0fbffff 8b85e0fbffff 8985ecfbffff } // n = 6, score = 100 // 51 | push ecx // e8???????? | // 83c404 | add esp, 4 // 8985e0fbffff | mov dword ptr [ebp - 0x420], eax // 8b85e0fbffff | mov eax, dword ptr [ebp - 0x420] // 8985ecfbffff | mov dword ptr [ebp - 0x414], eax $sequence_2 = { 8b4dfc 0fbe5103 83fa3e 750f } // n = 4, score = 100 // 8b4dfc | mov ecx, dword ptr [ebp - 4] // 0fbe5103 | movsx edx, byte ptr [ecx + 3] // 83fa3e | cmp edx, 0x3e // 750f | jne 0x11 $sequence_3 = { 0f8408000000 0f8502000000 ebe9 c745dc00000000 } // n = 4, score = 100 // 0f8408000000 | je 0xe // 0f8502000000 | jne 8 // ebe9 | jmp 0xffffffeb // c745dc00000000 | mov dword ptr [ebp - 0x24], 0 $sequence_4 = { 8b55f8 2b55fc 8955f8 ebb7 8b4510 5f } // n = 6, score = 100 // 8b55f8 | mov edx, dword ptr [ebp - 8] // 2b55fc | sub edx, dword ptr [ebp - 4] // 8955f8 | mov dword ptr [ebp - 8], edx // ebb7 | jmp 0xffffffb9 // 8b4510 | mov eax, dword ptr [ebp + 0x10] // 5f | pop edi $sequence_5 = { 51 8b55f4 52 8d4de4 e8???????? 8b45e8 } // n = 6, score = 100 // 51 | push ecx // 8b55f4 | mov edx, dword ptr [ebp - 0xc] // 52 | push edx // 8d4de4 | lea ecx, [ebp - 0x1c] // e8???????? | // 8b45e8 | mov eax, dword ptr [ebp - 0x18] $sequence_6 = { 8b4dfc 83c10b 894df4 6a20 } // n = 4, score = 100 // 8b4dfc | mov ecx, dword ptr [ebp - 4] // 83c10b | add ecx, 0xb // 894df4 | mov dword ptr [ebp - 0xc], ecx // 6a20 | push 0x20 $sequence_7 = { 8d41fc 8b4c2404 2bc1 c3 6800000300 } // n = 5, score = 100 // 8d41fc | lea eax, [ecx - 4] // 8b4c2404 | mov ecx, dword ptr [esp + 4] // 2bc1 | sub eax, ecx // c3 | ret // 6800000300 | push 0x30000 $sequence_8 = { 8dbdecfeffff 83c9ff 33c0 f2ae f7d1 83c1ff } // n = 6, score = 100 // 8dbdecfeffff | lea edi, [ebp - 0x114] // 83c9ff | or ecx, 0xffffffff // 33c0 | xor eax, eax // f2ae | repne scasb al, byte ptr es:[edi] // f7d1 | not ecx // 83c1ff | add ecx, -1 $sequence_9 = { 51 8b55f4 52 8d4de4 e8???????? } // n = 5, score = 100 // 51 | push ecx // 8b55f4 | mov edx, dword ptr [ebp - 0xc] // 52 | push edx // 8d4de4 | lea ecx, [ebp - 0x1c] // e8???????? | condition: 7 of them and filesize < 114688 }
If your designated proposal does not fit in any other category, feel free to write a free-text in the comment field below. Changes regarding references should be proposed on the Malpedia library page.
Your suggestion will be reviewed before being published. Thank you for contributing!
YYYY-MM-DD
YYYY-MM
YYYY