Actor(s): Leviathan
An uploader that can exfiltrate files to Dropbox.
rule win_lunchmoney_auto { meta: author = "Felix Bilstein - yara-signator at cocacoding dot com" date = "2023-12-06" version = "1" description = "Detects win.lunchmoney." 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.lunchmoney" malpedia_rule_date = "20231130" malpedia_hash = "fc8a0e9f343f6d6ded9e7df1a64dac0cc68d7351" malpedia_version = "20230808" 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 = { 8b4304 8d4b0c 83791408 8945dc 8b4308 8945e0 7202 } // n = 7, score = 100 // 8b4304 | mov eax, dword ptr [ebx + 4] // 8d4b0c | lea ecx, [ebx + 0xc] // 83791408 | cmp dword ptr [ecx + 0x14], 8 // 8945dc | mov dword ptr [ebp - 0x24], eax // 8b4308 | mov eax, dword ptr [ebx + 8] // 8945e0 | mov dword ptr [ebp - 0x20], eax // 7202 | jb 4 $sequence_1 = { 7405 e8???????? a900000080 751f d9fa 833d????????00 0f85f38b0000 } // n = 7, score = 100 // 7405 | je 7 // e8???????? | // a900000080 | test eax, 0x80000000 // 751f | jne 0x21 // d9fa | fsqrt // 833d????????00 | // 0f85f38b0000 | jne 0x8bf9 $sequence_2 = { c1e60a 56 e8???????? 56 8bf8 6a00 57 } // n = 7, score = 100 // c1e60a | shl esi, 0xa // 56 | push esi // e8???????? | // 56 | push esi // 8bf8 | mov edi, eax // 6a00 | push 0 // 57 | push edi $sequence_3 = { 53 8d4d08 e8???????? 83f8ff 750e 68???????? } // n = 6, score = 100 // 53 | push ebx // 8d4d08 | lea ecx, [ebp + 8] // e8???????? | // 83f8ff | cmp eax, -1 // 750e | jne 0x10 // 68???????? | $sequence_4 = { 8d4dd4 e8???????? 83f8ff 742d 6aff 40 } // n = 6, score = 100 // 8d4dd4 | lea ecx, [ebp - 0x2c] // e8???????? | // 83f8ff | cmp eax, -1 // 742d | je 0x2f // 6aff | push -1 // 40 | inc eax $sequence_5 = { 7420 53 8d85dcfeffff 50 } // n = 4, score = 100 // 7420 | je 0x22 // 53 | push ebx // 8d85dcfeffff | lea eax, [ebp - 0x124] // 50 | push eax $sequence_6 = { ff7580 e8???????? 8b8568ffffff 014588 59 83957cffffff00 837d0800 } // n = 7, score = 100 // ff7580 | push dword ptr [ebp - 0x80] // e8???????? | // 8b8568ffffff | mov eax, dword ptr [ebp - 0x98] // 014588 | add dword ptr [ebp - 0x78], eax // 59 | pop ecx // 83957cffffff00 | adc dword ptr [ebp - 0x84], 0 // 837d0800 | cmp dword ptr [ebp + 8], 0 $sequence_7 = { 8bcf e8???????? 837f1408 8bc8 } // n = 4, score = 100 // 8bcf | mov ecx, edi // e8???????? | // 837f1408 | cmp dword ptr [edi + 0x14], 8 // 8bc8 | mov ecx, eax $sequence_8 = { 8bc3 e8???????? c3 53 56 8bf1 57 } // n = 7, score = 100 // 8bc3 | mov eax, ebx // e8???????? | // c3 | ret // 53 | push ebx // 56 | push esi // 8bf1 | mov esi, ecx // 57 | push edi $sequence_9 = { 8d86f8000000 83c124 3bc8 740a 6aff 6a00 50 } // n = 7, score = 100 // 8d86f8000000 | lea eax, [esi + 0xf8] // 83c124 | add ecx, 0x24 // 3bc8 | cmp ecx, eax // 740a | je 0xc // 6aff | push -1 // 6a00 | push 0 // 50 | push eax condition: 7 of them and filesize < 373760 }
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