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 = "2022-04-08" 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 = "20220405" malpedia_hash = "ecd38294bd47d5589be5cd5490dc8bb4804afc2a" malpedia_version = "20220411" 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 = { 8bd0 e8???????? e9???????? 8d45a8 8bcf 50 e8???????? } // n = 7, score = 100 // 8bd0 | mov edx, eax // e8???????? | // e9???????? | // 8d45a8 | lea eax, dword ptr [ebp - 0x58] // 8bcf | mov ecx, edi // 50 | push eax // e8???????? | $sequence_1 = { 8365fc00 8d4508 81c1d4000000 3bc8 740a 6aff 6a00 } // n = 7, score = 100 // 8365fc00 | and dword ptr [ebp - 4], 0 // 8d4508 | lea eax, dword ptr [ebp + 8] // 81c1d4000000 | add ecx, 0xd4 // 3bc8 | cmp ecx, eax // 740a | je 0xc // 6aff | push -1 // 6a00 | push 0 $sequence_2 = { 85f6 7418 6a03 8802 42 8b048d50914200 4e } // n = 7, score = 100 // 85f6 | test esi, esi // 7418 | je 0x1a // 6a03 | push 3 // 8802 | mov byte ptr [edx], al // 42 | inc edx // 8b048d50914200 | mov eax, dword ptr [ecx*4 + 0x429150] // 4e | dec esi $sequence_3 = { 68???????? 8d45c4 c745c438044200 50 e8???????? ff7524 e8???????? } // n = 7, score = 100 // 68???????? | // 8d45c4 | lea eax, dword ptr [ebp - 0x3c] // c745c438044200 | mov dword ptr [ebp - 0x3c], 0x420438 // 50 | push eax // e8???????? | // ff7524 | push dword ptr [ebp + 0x24] // e8???????? | $sequence_4 = { 8d55f0 0f434d08 e8???????? 8bf0 6a00 56 e8???????? } // n = 7, score = 100 // 8d55f0 | lea edx, dword ptr [ebp - 0x10] // 0f434d08 | cmovae ecx, dword ptr [ebp + 8] // e8???????? | // 8bf0 | mov esi, eax // 6a00 | push 0 // 56 | push esi // e8???????? | $sequence_5 = { 59 85c0 7505 83c8ff eb02 8bc6 5e } // n = 7, score = 100 // 59 | pop ecx // 85c0 | test eax, eax // 7505 | jne 7 // 83c8ff | or eax, 0xffffffff // eb02 | jmp 4 // 8bc6 | mov eax, esi // 5e | pop esi $sequence_6 = { 8d45c0 50 e8???????? 83781408 7202 8b00 } // n = 6, score = 100 // 8d45c0 | lea eax, dword ptr [ebp - 0x40] // 50 | push eax // e8???????? | // 83781408 | cmp dword ptr [eax + 0x14], 8 // 7202 | jb 4 // 8b00 | mov eax, dword ptr [eax] $sequence_7 = { 6800000080 56 ff15???????? 8bf8 83ffff 7504 } // n = 6, score = 100 // 6800000080 | push 0x80000000 // 56 | push esi // ff15???????? | // 8bf8 | mov edi, eax // 83ffff | cmp edi, -1 // 7504 | jne 6 $sequence_8 = { ff15???????? 33db 8d8e34010000 33ff 53 47 57 } // n = 7, score = 100 // ff15???????? | // 33db | xor ebx, ebx // 8d8e34010000 | lea ecx, dword ptr [esi + 0x134] // 33ff | xor edi, edi // 53 | push ebx // 47 | inc edi // 57 | push edi $sequence_9 = { 56 e8???????? 8bcb e8???????? 8b8fc0000000 be00400000 8b97bc000000 } // n = 7, score = 100 // 56 | push esi // e8???????? | // 8bcb | mov ecx, ebx // e8???????? | // 8b8fc0000000 | mov ecx, dword ptr [edi + 0xc0] // be00400000 | mov esi, 0x4000 // 8b97bc000000 | mov edx, dword ptr [edi + 0xbc] condition: 7 of them and filesize < 373760 }
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