Ransomware.
rule win_thunderx_auto { meta: author = "Felix Bilstein - yara-signator at cocacoding dot com" date = "2023-07-11" 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 = "20230705" malpedia_hash = "42d0574f4405bd7d2b154d321d345acb18834a41" malpedia_version = "20230715" 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 = { b9???????? 83f801 0f45ca 51 8d8d30ffffff e8???????? } // n = 6, score = 200 // b9???????? | // 83f801 | cmp eax, 1 // 0f45ca | cmovne ecx, edx // 51 | push ecx // 8d8d30ffffff | lea ecx, [ebp - 0xd0] // e8???????? | $sequence_1 = { 0f847b010000 8d442410 895c2410 50 56 895c241c ff15???????? } // n = 7, score = 200 // 0f847b010000 | je 0x181 // 8d442410 | lea eax, [esp + 0x10] // 895c2410 | mov dword ptr [esp + 0x10], ebx // 50 | push eax // 56 | push esi // 895c241c | mov dword ptr [esp + 0x1c], ebx // ff15???????? | $sequence_2 = { 57 53 56 897e10 e8???????? 83c40c 881c37 } // n = 7, score = 200 // 57 | push edi // 53 | push ebx // 56 | push esi // 897e10 | mov dword ptr [esi + 0x10], edi // e8???????? | // 83c40c | add esp, 0xc // 881c37 | mov byte ptr [edi + esi], bl $sequence_3 = { 68???????? 8d4dd4 e8???????? c645fc01 3b75e4 7713 } // n = 6, score = 200 // 68???????? | // 8d4dd4 | lea ecx, [ebp - 0x2c] // e8???????? | // c645fc01 | mov byte ptr [ebp - 4], 1 // 3b75e4 | cmp esi, dword ptr [ebp - 0x1c] // 7713 | ja 0x15 $sequence_4 = { f7f9 8bce 6bd01c e8???????? 8b45fc 6bcb1c 893d???????? } // n = 7, score = 200 // f7f9 | idiv ecx // 8bce | mov ecx, esi // 6bd01c | imul edx, eax, 0x1c // e8???????? | // 8b45fc | mov eax, dword ptr [ebp - 4] // 6bcb1c | imul ecx, ebx, 0x1c // 893d???????? | $sequence_5 = { ff35???????? ff15???????? 8b75ec 85f6 74d3 85c0 74cf } // n = 7, score = 200 // ff35???????? | // ff15???????? | // 8b75ec | mov esi, dword ptr [ebp - 0x14] // 85f6 | test esi, esi // 74d3 | je 0xffffffd5 // 85c0 | test eax, eax // 74cf | je 0xffffffd1 $sequence_6 = { be???????? c645fc07 56 8bd0 8d8d18ffffff e8???????? 59 } // n = 7, score = 200 // be???????? | // c645fc07 | mov byte ptr [ebp - 4], 7 // 56 | push esi // 8bd0 | mov edx, eax // 8d8d18ffffff | lea ecx, [ebp - 0xe8] // e8???????? | // 59 | pop ecx $sequence_7 = { 85c0 7412 8b7d98 8b459c eb10 8d4de4 e8???????? } // n = 7, score = 200 // 85c0 | test eax, eax // 7412 | je 0x14 // 8b7d98 | mov edi, dword ptr [ebp - 0x68] // 8b459c | mov eax, dword ptr [ebp - 0x64] // eb10 | jmp 0x12 // 8d4de4 | lea ecx, [ebp - 0x1c] // e8???????? | $sequence_8 = { 8b442424 81c70000a000 13c3 89442424 3b442414 0f8c49ffffff } // n = 6, score = 200 // 8b442424 | mov eax, dword ptr [esp + 0x24] // 81c70000a000 | add edi, 0xa00000 // 13c3 | adc eax, ebx // 89442424 | mov dword ptr [esp + 0x24], eax // 3b442414 | cmp eax, dword ptr [esp + 0x14] // 0f8c49ffffff | jl 0xffffff4f $sequence_9 = { b8???????? e8???????? 803d????????00 7478 33ff 897dfc } // n = 6, score = 200 // b8???????? | // e8???????? | // 803d????????00 | // 7478 | je 0x7a // 33ff | xor edi, edi // 897dfc | mov dword ptr [ebp - 4], edi 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