Ransomware.
rule win_thunderx_auto { meta: author = "Felix Bilstein - yara-signator at cocacoding dot com" date = "2023-03-28" version = "1" description = "Detects win.thunderx." 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.thunderx" malpedia_rule_date = "20230328" malpedia_hash = "9d2d75cef573c1c2d861f5197df8f563b05a305d" malpedia_version = "20230407" 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 = { 395710 7507 32c0 e9???????? 837f1410 8bc7 8955fc } // n = 7, score = 200 // 395710 | cmp dword ptr [edi + 0x10], edx // 7507 | jne 9 // 32c0 | xor al, al // e9???????? | // 837f1410 | cmp dword ptr [edi + 0x14], 0x10 // 8bc7 | mov eax, edi // 8955fc | mov dword ptr [ebp - 4], edx $sequence_1 = { 8b550c 8d045a 3bc1 7617 } // n = 4, score = 200 // 8b550c | mov edx, dword ptr [ebp + 0xc] // 8d045a | lea eax, [edx + ebx*2] // 3bc1 | cmp eax, ecx // 7617 | jbe 0x19 $sequence_2 = { 897318 8d7b1c 33c0 ab 53 6a01 } // n = 6, score = 200 // 897318 | mov dword ptr [ebx + 0x18], esi // 8d7b1c | lea edi, [ebx + 0x1c] // 33c0 | xor eax, eax // ab | stosd dword ptr es:[edi], eax // 53 | push ebx // 6a01 | push 1 $sequence_3 = { 83e4f8 81ec14010000 a1???????? 33c4 89842410010000 8b4510 89442408 } // n = 7, score = 200 // 83e4f8 | and esp, 0xfffffff8 // 81ec14010000 | sub esp, 0x114 // a1???????? | // 33c4 | xor eax, esp // 89842410010000 | mov dword ptr [esp + 0x110], eax // 8b4510 | mov eax, dword ptr [ebp + 0x10] // 89442408 | mov dword ptr [esp + 8], eax $sequence_4 = { 8b4048 f00fc118 4b 7515 8b4510 81784820014200 7409 } // n = 7, score = 200 // 8b4048 | mov eax, dword ptr [eax + 0x48] // f00fc118 | lock xadd dword ptr [eax], ebx // 4b | dec ebx // 7515 | jne 0x17 // 8b4510 | mov eax, dword ptr [ebp + 0x10] // 81784820014200 | cmp dword ptr [eax + 0x48], 0x420120 // 7409 | je 0xb $sequence_5 = { 8d4dd8 7407 e8???????? eb50 e8???????? 6a30 8bf0 } // n = 7, score = 200 // 8d4dd8 | lea ecx, [ebp - 0x28] // 7407 | je 9 // e8???????? | // eb50 | jmp 0x52 // e8???????? | // 6a30 | push 0x30 // 8bf0 | mov esi, eax $sequence_6 = { 5b 5f 5d c20800 6a38 b8???????? e8???????? } // n = 7, score = 200 // 5b | pop ebx // 5f | pop edi // 5d | pop ebp // c20800 | ret 8 // 6a38 | push 0x38 // b8???????? | // e8???????? | $sequence_7 = { a1???????? 83c0e4 83781408 7202 8b00 53 } // n = 6, score = 200 // a1???????? | // 83c0e4 | add eax, -0x1c // 83781408 | cmp dword ptr [eax + 0x14], 8 // 7202 | jb 4 // 8b00 | mov eax, dword ptr [eax] // 53 | push ebx $sequence_8 = { 55 8bec 8bd1 8b4d08 57 8b4214 8b7a10 } // n = 7, score = 200 // 55 | push ebp // 8bec | mov ebp, esp // 8bd1 | mov edx, ecx // 8b4d08 | mov ecx, dword ptr [ebp + 8] // 57 | push edi // 8b4214 | mov eax, dword ptr [edx + 0x14] // 8b7a10 | mov edi, dword ptr [edx + 0x10] $sequence_9 = { 8d7608 660fd60f 8d7f08 8b048dc49f4000 ffe0 f7c703000000 } // n = 6, score = 200 // 8d7608 | lea esi, [esi + 8] // 660fd60f | movq qword ptr [edi], xmm1 // 8d7f08 | lea edi, [edi + 8] // 8b048dc49f4000 | mov eax, dword ptr [ecx*4 + 0x409fc4] // ffe0 | jmp eax // f7c703000000 | test edi, 3 condition: 7 of them and filesize < 319488 }
import "pe" rule win_thunderx_w0 { meta: description = "Rule to dettect tthe ThunderX ransomware family" author = "Christiaan Beek @ McAfee ATR team" date = "2020-09-14" rule_version = "v1" malware_type = "ransomware" malware_family = "Ransomware:W32/ThunderX" actor_type = "Cybercrime" actor_group = "Unknown" hash1 = "7bab5dedef124803668580a59b6bf3c53cc31150d19591567397bbc131b9ccb6" hash2 = "0fbfdb8340108fafaca4c5ff4d3c9f9a2296efeb9ae89fcd9210e3d4c7239666" hash3 = "7527459500109b3bb48665236c5c5cb2ec71ba789867ad2b6417b38b9a46615e" source = "https://github.com/advanced-threat-research/Yara-Rules/blob/master/ransomware/Ransom_ThunderX.yar" malpedia_reference = "https://malpedia.caad.fkie.fraunhofer.de/details/win.thunderx" malpedia_rule_date = "20200915" malpedia_hash = "" malpedia_version = "20200915" malpedia_license = "CC BY-SA 4.0" malpedia_sharing = "TLP:WHITE" strings: $pattern1 = "626364656469742E657865202F736574207B64656661756C747D20626F6F74737461747573706F6C6963792069676E6F7265616C6C6661696C75726573" $s3 = "776261646D696E2044454C4554452053595354454D53544154454241434B5550202D64656C6574654F6C64657374" ascii $s4 = "626364656469742E657865202F736574207B64656661756C747D207265636F76657279656E61626C6564204E6F" ascii $s5 = "776261646D696E2044454C4554452053595354454D53544154454241434B5550" ascii $s6 = "433A5C50726F6772616D2046696C65732028783836295C4D6963726F736F66742053514C20536572766572" ascii $s7 = "476C6F62616C5C33353335354641352D303745392D343238422D423541352D314338384341423242343838" ascii $s8 = "433A5C50726F6772616D2046696C65735C4D6963726F736F66742053514C20536572766572" ascii $s9 = "76737361646D696E2E6578652044656C65746520536861646F7773202F416C6C202F5175696574" ascii $s10 = "776D69632E65786520534841444F57434F5059202F6E6F696E746572616374697665" ascii $s11 = "534F4654574152455C4D6963726F736F66745C45524944" ascii $s12 = "AppPolicyGetProcessTerminationMethod" fullword ascii $s13 = "7B5041545445524E5F49447D" ascii $s14 = "726561646D652E747874" ascii $s15 = "226E6574776F726B223A22" ascii $s16 = "227375626964223A22" ascii $s17 = "226C616E67223A22" ascii $s18 = "22657874223A22" ascii $s19 = "69642E6B6579" ascii $s20 = "7B5549447D" ascii $seq0 = { eb 34 66 0f 12 0d 10 c4 41 00 f2 0f 59 c1 ba cc } $seq1 = { 6a 07 50 e8 51 ff ff ff 8d 86 d0 } $seq2 = { ff 15 34 81 41 00 eb 15 83 f8 fc 75 10 8b 45 f4 } condition: ( uint16(0) == 0x5a4d and filesize < 400KB and pe.imphash() == "ea7e408cd2a264fd13492973e97d8d70" and $pattern1 and 4 of them ) and all of ($seq*) or ( all of them ) }
If your designated proposal does not fit in any other category, feel free to write a free-text in the comment field below.
Please propose all changes regarding references on the Malpedia library page
Your suggestion will be reviewed before being published. Thank you for contributing!
YYYY-MM-DD
YYYY-MM
YYYY