Frank Boldewin describes Loup as a small cli-tool to cash out NCR devices (ATM).
rule win_loup_auto { meta: author = "Felix Bilstein - yara-signator at cocacoding dot com" date = "2026-01-05" version = "1" description = "Detects win.loup." 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.loup" 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 = { 8b4508 50 8d8de0fbffff 51 8d95f0fdffff 52 } // n = 6, score = 100 // 8b4508 | mov eax, dword ptr [ebp + 8] // 50 | push eax // 8d8de0fbffff | lea ecx, [ebp - 0x420] // 51 | push ecx // 8d95f0fdffff | lea edx, [ebp - 0x210] // 52 | push edx $sequence_1 = { 668945e8 33c0 668945ea c745ee01000000 b804000000 } // n = 5, score = 100 // 668945e8 | mov word ptr [ebp - 0x18], ax // 33c0 | xor eax, eax // 668945ea | mov word ptr [ebp - 0x16], ax // c745ee01000000 | mov dword ptr [ebp - 0x12], 1 // b804000000 | mov eax, 4 $sequence_2 = { 8d15341a4100 e8???????? 58 5a 5f 5e } // n = 6, score = 100 // 8d15341a4100 | lea edx, [0x411a34] // e8???????? | // 58 | pop eax // 5a | pop edx // 5f | pop edi // 5e | pop esi $sequence_3 = { 33c5 8945fc b9???????? e8???????? c745c000000000 c745b400000000 } // n = 6, score = 100 // 33c5 | xor eax, ebp // 8945fc | mov dword ptr [ebp - 4], eax // b9???????? | // e8???????? | // c745c000000000 | mov dword ptr [ebp - 0x40], 0 // c745b400000000 | mov dword ptr [ebp - 0x4c], 0 $sequence_4 = { c784055cffffff01000000 8d855cffffff 8945d5 8bf4 6a03 } // n = 5, score = 100 // c784055cffffff01000000 | mov dword ptr [ebp + eax - 0xa4], 1 // 8d855cffffff | lea eax, [ebp - 0xa4] // 8945d5 | mov dword ptr [ebp - 0x2b], eax // 8bf4 | mov esi, esp // 6a03 | push 3 $sequence_5 = { 7709 8b048514824100 5d c3 33c0 } // n = 5, score = 100 // 7709 | ja 0xb // 8b048514824100 | mov eax, dword ptr [eax*4 + 0x418214] // 5d | pop ebp // c3 | ret // 33c0 | xor eax, eax $sequence_6 = { c705????????01000000 b904000000 6bd100 c78264a1410002000000 b804000000 6bc800 } // n = 6, score = 100 // c705????????01000000 | // b904000000 | mov ecx, 4 // 6bd100 | imul edx, ecx, 0 // c78264a1410002000000 | mov dword ptr [edx + 0x41a164], 2 // b804000000 | mov eax, 4 // 6bc800 | imul ecx, eax, 0 $sequence_7 = { a1???????? 8985c4fbffff 8b0d???????? 898dc8fbffff 8b15???????? } // n = 5, score = 100 // a1???????? | // 8985c4fbffff | mov dword ptr [ebp - 0x43c], eax // 8b0d???????? | // 898dc8fbffff | mov dword ptr [ebp - 0x438], ecx // 8b15???????? | $sequence_8 = { 668945e8 33c0 668945ea c745ee01000000 } // n = 4, score = 100 // 668945e8 | mov word ptr [ebp - 0x18], ax // 33c0 | xor eax, eax // 668945ea | mov word ptr [ebp - 0x16], ax // c745ee01000000 | mov dword ptr [ebp - 0x12], 1 $sequence_9 = { 51 e8???????? 85c0 7513 8b45f4 50 e8???????? } // n = 7, score = 100 // 51 | push ecx // e8???????? | // 85c0 | test eax, eax // 7513 | jne 0x15 // 8b45f4 | mov eax, dword ptr [ebp - 0xc] // 50 | push eax // e8???????? | condition: 7 of them and filesize < 257024 }
rule win_loup_w0 { meta: description = "Detects of ATM Malware Loup" author = "Frank Boldewin (@r3c0nst)" reference = "https://twitter.com/r3c0nst/status/1295275546780327936" source = "https://raw.githubusercontent.com/fboldewin/YARA-rules/master/ATM.Malware.Loup.yar" date = "2020-08-17" hash = "6c9e9f78963ab3e7acb43826906af22571250dc025f9e7116e0201b805dc1196" malpedia_reference = "https://malpedia.caad.fkie.fraunhofer.de/details/win.loup" malpedia_rule_date = "20200817" malpedia_version = "20200817" malpedia_license = "CC BY-SA 4.0" malpedia_sharing = "TLP:WHITE" strings: $String1 = "C:\\Users\\muham\\source\\repos\\loup\\Debug\\loup.pdb" ascii nocase $String2 = "CurrencyDispenser1" ascii nocase $Code = {50 68 C0 D4 01 00 8D 4D E8 51 68 2E 01 00 00 0F B7 55 08 52 E8} // Dispense condition: uint16(0) == 0x5A4D and filesize < 100KB and all of ($String*) and $Code }
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