Browser information stealer, written in Go.
rule win_hackbrowserdata_auto { meta: author = "Felix Bilstein - yara-signator at cocacoding dot com" date = "2026-01-05" version = "1" description = "Detects win.hackbrowserdata." 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.hackbrowserdata" 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 = { ffc1 4d89ea 4d89fc 4989fd 4d89e7 41394c2428 0f8e0dfaffff } // n = 7, score = 100 // ffc1 | mov dword ptr [esp + 0x28], eax // 4d89ea | dec eax // 4d89fc | mov dword ptr [eax], 0 // 4989fd | dec eax // 4d89e7 | mov dword ptr [esp + 0x18], eax // 41394c2428 | mov byte ptr [eax], 0xb6 // 0f8e0dfaffff | dec eax $sequence_1 = { f20f1005???????? 31db 49c7c0ffffffff eb3d 48890437 488bb424a0000000 4883c618 } // n = 7, score = 100 // f20f1005???????? | // 31db | test dl, dl // 49c7c0ffffffff | je 0x6d8 // eb3d | dec eax // 48890437 | cmp eax, 1 // 488bb424a0000000 | je 0x6c6 // 4883c618 | dec eax $sequence_2 = { e8???????? 488b542450 48895008 833d????????00 750a 488b9424d8000000 eb10 } // n = 7, score = 100 // e8???????? | // 488b542450 | mov eax, 0x49 // 48895008 | call ecx // 833d????????00 | // 750a | dec eax // 488b9424d8000000 | mov ecx, dword ptr [eax] // eb10 | dec eax $sequence_3 = { e8???????? e9???????? 488b1d???????? 4881c368960000 488b442478 488b4c2448 e8???????? } // n = 7, score = 100 // e8???????? | // e9???????? | // 488b1d???????? | // 4881c368960000 | dec eax // 488b442478 | mov edi, dword ptr [esp + 0x48] // 488b4c2448 | dec eax // e8???????? | $sequence_4 = { ffd3 833d????????00 7507 488b742408 eb15 e8???????? 498903 } // n = 7, score = 100 // ffd3 | dec eax // 833d????????00 | // 7507 | mov dword ptr [eax], 0 // 488b742408 | dec eax // eb15 | lea eax, [0x9ceffb] // e8???????? | // 498903 | dec eax $sequence_5 = { e9???????? 488d4f54 4889ca 0fb619 ffcb 8819 480fbe0a } // n = 7, score = 100 // e9???????? | // 488d4f54 | mov dword ptr [esp + 0x50], ebx // 4889ca | inc esp // 0fb619 | movups xmmword ptr [esp + 0xb0], xmm7 // ffcb | dec eax // 8819 | mov eax, dword ptr [esp + 0x48] // 480fbe0a | ret $sequence_6 = { f20f59d8 f20f581d???????? f20f59d8 f20f581d???????? f20f59d8 f20f581d???????? f20f59d9 } // n = 7, score = 100 // f20f59d8 | jne 0xa07 // f20f581d???????? | // f20f59d8 | dec eax // f20f581d???????? | // f20f59d8 | lea eax, [0x9d80af] // f20f581d???????? | // f20f59d9 | dec eax $sequence_7 = { ffc1 39d1 7d5d 4889f7 488b7640 4c63c1 4a8d34c6 } // n = 7, score = 100 // ffc1 | mov byte ptr [eax], 0x90 // 39d1 | dec eax // 7d5d | lea eax, [0x91f3b3] // 4889f7 | dec eax // 488b7640 | mov dword ptr [esp + 0x28], eax // 4c63c1 | dec eax // 4a8d34c6 | mov dword ptr [eax], 0 $sequence_8 = { eb13 4883c420 5d c3 48bfffffffffffff0300 4989da 4585c0 } // n = 7, score = 100 // eb13 | dec eax // 4883c420 | mov ebx, dword ptr [esp + 0x180] // 5d | dec eax // c3 | mov edx, ebx // 48bfffffffffffff0300 | movzx edx, byte ptr [edx] // 4989da | dec eax // 4585c0 | lea esi, [0xe8d4dc] $sequence_9 = { e8???????? 498913 48895018 488b942480000000 488b5c2470 4889f9 4c89c7 } // n = 7, score = 100 // e8???????? | // 498913 | nop // 48895018 | dec eax // 488b942480000000 | lea eax, [0x56539c] // 488b5c2470 | mov ebx, 1 // 4889f9 | dec eax // 4c89c7 | mov dword ptr [esp + 0x260], eax condition: 7 of them and filesize < 42451968 }
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