Ransomware, potential rebranding of win.sfile.
rule win_mindware_auto { meta: author = "Felix Bilstein - yara-signator at cocacoding dot com" date = "2026-01-05" version = "1" description = "Detects win.mindware." 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.mindware" 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 = { 68???????? e8???????? 83c40c 8b4dfc 8b7dfc 83c72c } // n = 6, score = 100 // 68???????? | // e8???????? | // 83c40c | add esp, 0xc // 8b4dfc | mov ecx, dword ptr [ebp - 4] // 8b7dfc | mov edi, dword ptr [ebp - 4] // 83c72c | add edi, 0x2c $sequence_1 = { 50 8b4d08 8b5108 8b4508 8b12 8b4808 } // n = 6, score = 100 // 50 | push eax // 8b4d08 | mov ecx, dword ptr [ebp + 8] // 8b5108 | mov edx, dword ptr [ecx + 8] // 8b4508 | mov eax, dword ptr [ebp + 8] // 8b12 | mov edx, dword ptr [edx] // 8b4808 | mov ecx, dword ptr [eax + 8] $sequence_2 = { c7855cecfffff8d44300 c78560ecffff00d54300 c78564ecffff0cd54300 c78568ecffff18d54300 c7856cecffff24d54300 c78570ecffff2cd54300 c78574ecffff34d54300 } // n = 7, score = 100 // c7855cecfffff8d44300 | mov dword ptr [ebp - 0x13a4], 0x43d4f8 // c78560ecffff00d54300 | mov dword ptr [ebp - 0x13a0], 0x43d500 // c78564ecffff0cd54300 | mov dword ptr [ebp - 0x139c], 0x43d50c // c78568ecffff18d54300 | mov dword ptr [ebp - 0x1398], 0x43d518 // c7856cecffff24d54300 | mov dword ptr [ebp - 0x1394], 0x43d524 // c78570ecffff2cd54300 | mov dword ptr [ebp - 0x1390], 0x43d52c // c78574ecffff34d54300 | mov dword ptr [ebp - 0x138c], 0x43d534 $sequence_3 = { c1e810 83e03f c1e918 83e13f 8b0c8d603a4400 330c8520394400 8bc2 } // n = 7, score = 100 // c1e810 | shr eax, 0x10 // 83e03f | and eax, 0x3f // c1e918 | shr ecx, 0x18 // 83e13f | and ecx, 0x3f // 8b0c8d603a4400 | mov ecx, dword ptr [ecx*4 + 0x443a60] // 330c8520394400 | xor ecx, dword ptr [eax*4 + 0x443920] // 8bc2 | mov eax, edx $sequence_4 = { 33148dc0bc4400 8bcb c1e918 33148dc0c44400 8b4df0 } // n = 5, score = 100 // 33148dc0bc4400 | xor edx, dword ptr [ecx*4 + 0x44bcc0] // 8bcb | mov ecx, ebx // c1e918 | shr ecx, 0x18 // 33148dc0c44400 | xor edx, dword ptr [ecx*4 + 0x44c4c0] // 8b4df0 | mov ecx, dword ptr [ebp - 0x10] $sequence_5 = { e8???????? 8b4dfc 51 e8???????? 8b55fc c7423000000000 8b45fc } // n = 7, score = 100 // e8???????? | // 8b4dfc | mov ecx, dword ptr [ebp - 4] // 51 | push ecx // e8???????? | // 8b55fc | mov edx, dword ptr [ebp - 4] // c7423000000000 | mov dword ptr [edx + 0x30], 0 // 8b45fc | mov eax, dword ptr [ebp - 4] $sequence_6 = { c78540f1ffffbce04300 c78544f1ffffc4e04300 c78548f1ffffcce04300 c7854cf1ffffd4e04300 c78550f1ffffe0e04300 c78554f1ffffece04300 c78558f1fffff4e04300 } // n = 7, score = 100 // c78540f1ffffbce04300 | mov dword ptr [ebp - 0xec0], 0x43e0bc // c78544f1ffffc4e04300 | mov dword ptr [ebp - 0xebc], 0x43e0c4 // c78548f1ffffcce04300 | mov dword ptr [ebp - 0xeb8], 0x43e0cc // c7854cf1ffffd4e04300 | mov dword ptr [ebp - 0xeb4], 0x43e0d4 // c78550f1ffffe0e04300 | mov dword ptr [ebp - 0xeb0], 0x43e0e0 // c78554f1ffffece04300 | mov dword ptr [ebp - 0xeac], 0x43e0ec // c78558f1fffff4e04300 | mov dword ptr [ebp - 0xea8], 0x43e0f4 $sequence_7 = { 83e03f 330c8520384400 330c95e03c4400 8bd3 33f1 c1ca04 33576c } // n = 7, score = 100 // 83e03f | and eax, 0x3f // 330c8520384400 | xor ecx, dword ptr [eax*4 + 0x443820] // 330c95e03c4400 | xor ecx, dword ptr [edx*4 + 0x443ce0] // 8bd3 | mov edx, ebx // 33f1 | xor esi, ecx // c1ca04 | ror edx, 4 // 33576c | xor edx, dword ptr [edi + 0x6c] $sequence_8 = { 8b4dfc 8b7dfc 83c72c 32c0 8b4928 } // n = 5, score = 100 // 8b4dfc | mov ecx, dword ptr [ebp - 4] // 8b7dfc | mov edi, dword ptr [ebp - 4] // 83c72c | add edi, 0x2c // 32c0 | xor al, al // 8b4928 | mov ecx, dword ptr [ecx + 0x28] $sequence_9 = { 0fb689f0d84400 c1e108 33d1 8b4df0 c1e908 0fb6c9 c1e208 } // n = 7, score = 100 // 0fb689f0d84400 | movzx ecx, byte ptr [ecx + 0x44d8f0] // c1e108 | shl ecx, 8 // 33d1 | xor edx, ecx // 8b4df0 | mov ecx, dword ptr [ebp - 0x10] // c1e908 | shr ecx, 8 // 0fb6c9 | movzx ecx, cl // c1e208 | shl edx, 8 condition: 7 of them and filesize < 661504 }
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