Actor(s): Lazarus Group
SHADYCAT is a dropper and spreader component for the HERMES 2.1 RANSOMWARE radical edition.
rule win_bitsran_auto { meta: author = "Felix Bilstein - yara-signator at cocacoding dot com" date = "2023-07-11" version = "1" description = "Detects win.bitsran." 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.bitsran" 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 = { c3 8bff 56 57 33ff ffb7b0104200 ff15???????? } // n = 7, score = 100 // c3 | ret // 8bff | mov edi, edi // 56 | push esi // 57 | push edi // 33ff | xor edi, edi // ffb7b0104200 | push dword ptr [edi + 0x4210b0] // ff15???????? | $sequence_1 = { 7515 5f b8384a0000 5e } // n = 4, score = 100 // 7515 | jne 0x17 // 5f | pop edi // b8384a0000 | mov eax, 0x4a38 // 5e | pop esi $sequence_2 = { 8b4510 33c9 66894804 89882c020000 8b4d08 } // n = 5, score = 100 // 8b4510 | mov eax, dword ptr [ebp + 0x10] // 33c9 | xor ecx, ecx // 66894804 | mov word ptr [eax + 4], cx // 89882c020000 | mov dword ptr [eax + 0x22c], ecx // 8b4d08 | mov ecx, dword ptr [ebp + 8] $sequence_3 = { d1f8 7517 57 ff15???????? } // n = 4, score = 100 // d1f8 | sar eax, 1 // 7517 | jne 0x19 // 57 | push edi // ff15???????? | $sequence_4 = { 53 57 ff15???????? 8985c4fcffff 85c0 0f840c020000 } // n = 6, score = 100 // 53 | push ebx // 57 | push edi // ff15???????? | // 8985c4fcffff | mov dword ptr [ebp - 0x33c], eax // 85c0 | test eax, eax // 0f840c020000 | je 0x212 $sequence_5 = { 742b 8bc1 2bc1 c1f802 8d348500000000 } // n = 5, score = 100 // 742b | je 0x2d // 8bc1 | mov eax, ecx // 2bc1 | sub eax, ecx // c1f802 | sar eax, 2 // 8d348500000000 | lea esi, [eax*4] $sequence_6 = { 6685c9 743f 33c0 8945ee 8945f2 8945f6 668945fa } // n = 7, score = 100 // 6685c9 | test cx, cx // 743f | je 0x41 // 33c0 | xor eax, eax // 8945ee | mov dword ptr [ebp - 0x12], eax // 8945f2 | mov dword ptr [ebp - 0xe], eax // 8945f6 | mov dword ptr [ebp - 0xa], eax // 668945fa | mov word ptr [ebp - 6], ax $sequence_7 = { e8???????? 83c40c 83f8ff 7440 50 e8???????? 83c404 } // n = 7, score = 100 // e8???????? | // 83c40c | add esp, 0xc // 83f8ff | cmp eax, -1 // 7440 | je 0x42 // 50 | push eax // e8???????? | // 83c404 | add esp, 4 $sequence_8 = { 56 668945ee e8???????? 8b4dfc 33cd } // n = 5, score = 100 // 56 | push esi // 668945ee | mov word ptr [ebp - 0x12], ax // e8???????? | // 8b4dfc | mov ecx, dword ptr [ebp - 4] // 33cd | xor ecx, ebp $sequence_9 = { 7407 838b0c02000002 84d2 7407 838b0c02000001 80bdecfcffff00 } // n = 6, score = 100 // 7407 | je 9 // 838b0c02000002 | or dword ptr [ebx + 0x20c], 2 // 84d2 | test dl, dl // 7407 | je 9 // 838b0c02000001 | or dword ptr [ebx + 0x20c], 1 // 80bdecfcffff00 | cmp byte ptr [ebp - 0x314], 0 condition: 7 of them and filesize < 344064 }
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