There is no description at this point.
rule win_orpcbackdoor_auto { meta: author = "Felix Bilstein - yara-signator at cocacoding dot com" date = "2024-10-31" version = "1" description = "Detects win.orpcbackdoor." 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.orpcbackdoor" malpedia_rule_date = "20241030" malpedia_hash = "26e26953c49c8efafbf72a38076855d578e0a2e4" malpedia_version = "20241030" 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 = { ff503c 89859cfdffff 83bd9cfdffff00 7d48 8b85d4fdffff 8b00 ffb5d4fdffff } // n = 7, score = 100 // ff503c | call dword ptr [eax + 0x3c] // 89859cfdffff | mov dword ptr [ebp - 0x264], eax // 83bd9cfdffff00 | cmp dword ptr [ebp - 0x264], 0 // 7d48 | jge 0x4a // 8b85d4fdffff | mov eax, dword ptr [ebp - 0x22c] // 8b00 | mov eax, dword ptr [eax] // ffb5d4fdffff | push dword ptr [ebp - 0x22c] $sequence_1 = { ff15???????? 8985b0feffff 8d85bcfeffff 50 ffb5b8feffff e8???????? 85c0 } // n = 7, score = 100 // ff15???????? | // 8985b0feffff | mov dword ptr [ebp - 0x150], eax // 8d85bcfeffff | lea eax, [ebp - 0x144] // 50 | push eax // ffb5b8feffff | push dword ptr [ebp - 0x148] // e8???????? | // 85c0 | test eax, eax $sequence_2 = { f20f59148590dc0310 660f5834c5a0e40310 660f54c5 f20f5ce8 f20f58fa f20f10d8 f20f59c1 } // n = 7, score = 100 // f20f59148590dc0310 | mulsd xmm2, qword ptr [eax*4 + 0x1003dc90] // 660f5834c5a0e40310 | addpd xmm6, xmmword ptr [eax*8 + 0x1003e4a0] // 660f54c5 | andpd xmm0, xmm5 // f20f5ce8 | subsd xmm5, xmm0 // f20f58fa | addsd xmm7, xmm2 // f20f10d8 | movsd xmm3, xmm0 // f20f59c1 | mulsd xmm0, xmm1 $sequence_3 = { 8b55fc 89440ae4 c9 c3 55 8bec 83ec0c } // n = 7, score = 100 // 8b55fc | mov edx, dword ptr [ebp - 4] // 89440ae4 | mov dword ptr [edx + ecx - 0x1c], eax // c9 | leave // c3 | ret // 55 | push ebp // 8bec | mov ebp, esp // 83ec0c | sub esp, 0xc $sequence_4 = { 8d85dcf7ffff 50 8d8d20ebffff e8???????? 8d8da7e6ffff e8???????? 50 } // n = 7, score = 100 // 8d85dcf7ffff | lea eax, [ebp - 0x824] // 50 | push eax // 8d8d20ebffff | lea ecx, [ebp - 0x14e0] // e8???????? | // 8d8da7e6ffff | lea ecx, [ebp - 0x1959] // e8???????? | // 50 | push eax $sequence_5 = { 83b8a800000000 750e 8b04bd20cc0610 807c182900 741d 8d45fc 50 } // n = 7, score = 100 // 83b8a800000000 | cmp dword ptr [eax + 0xa8], 0 // 750e | jne 0x10 // 8b04bd20cc0610 | mov eax, dword ptr [edi*4 + 0x1006cc20] // 807c182900 | cmp byte ptr [eax + ebx + 0x29], 0 // 741d | je 0x1f // 8d45fc | lea eax, [ebp - 4] // 50 | push eax $sequence_6 = { c3 85c0 78f5 8b1cc554a30310 6a55 53 e8???????? } // n = 7, score = 100 // c3 | ret // 85c0 | test eax, eax // 78f5 | js 0xfffffff7 // 8b1cc554a30310 | mov ebx, dword ptr [eax*8 + 0x1003a354] // 6a55 | push 0x55 // 53 | push ebx // e8???????? | $sequence_7 = { 8b4508 8945f4 c645f801 8b45f0 83c004 50 } // n = 6, score = 100 // 8b4508 | mov eax, dword ptr [ebp + 8] // 8945f4 | mov dword ptr [ebp - 0xc], eax // c645f801 | mov byte ptr [ebp - 8], 1 // 8b45f0 | mov eax, dword ptr [ebp - 0x10] // 83c004 | add eax, 4 // 50 | push eax $sequence_8 = { 8b45fc 83c004 50 e8???????? 59 c9 c3 } // n = 7, score = 100 // 8b45fc | mov eax, dword ptr [ebp - 4] // 83c004 | add eax, 4 // 50 | push eax // e8???????? | // 59 | pop ecx // c9 | leave // c3 | ret $sequence_9 = { e8???????? 59 8b45fc 8b4010 40 50 ff75f8 } // n = 7, score = 100 // e8???????? | // 59 | pop ecx // 8b45fc | mov eax, dword ptr [ebp - 4] // 8b4010 | mov eax, dword ptr [eax + 0x10] // 40 | inc eax // 50 | push eax // ff75f8 | push dword ptr [ebp - 8] condition: 7 of them and filesize < 918528 }
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