According to Cyble, this is a stealer targeting several crypto currency wallets along browser data.
rule win_temp_stealer_auto { meta: author = "Felix Bilstein - yara-signator at cocacoding dot com" date = "2023-12-06" version = "1" description = "Detects win.temp_stealer." 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.temp_stealer" malpedia_rule_date = "20231130" malpedia_hash = "fc8a0e9f343f6d6ded9e7df1a64dac0cc68d7351" malpedia_version = "20230808" 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 = { 4d8bc7 498bce e8???????? 4885c0 7405 492bc6 eb04 } // n = 7, score = 100 // 4d8bc7 | dec eax // 498bce | mov dword ptr [esp + 0x30], 1 // e8???????? | // 4885c0 | dec eax // 7405 | lea eax, [0x3b462] // 492bc6 | dec eax // eb04 | cmp esi, 1 $sequence_1 = { 488d4c2430 e8???????? 488b442430 48635004 488d051a730300 4889441430 488b442430 } // n = 7, score = 100 // 488d4c2430 | lea edx, [esp + 0x50] // e8???????? | // 488b442430 | dec eax // 48635004 | lea ecx, [esp + 0x40] // 488d051a730300 | movups xmmword ptr [ebp + 0x27], xmm1 // 4889441430 | dec esp // 488b442430 | mov dword ptr [ebp - 0x49], esi $sequence_2 = { 5e 5d c3 4889542410 48894c2408 55 53 } // n = 7, score = 100 // 5e | dec esp // 5d | mov dword ptr [esp + 0x40], ebp // c3 | dec esp // 4889542410 | mov dword ptr [esp + 0x50], ebp // 48894c2408 | dec eax // 55 | mov dword ptr [esp + 0x20], edx // 53 | dec eax $sequence_3 = { 488d4dc0 e8???????? 0f10442460 0f1145c0 0f104c2470 0f114dd0 660f6f05???????? } // n = 7, score = 100 // 488d4dc0 | nop word ptr [eax + eax] // e8???????? | // 0f10442460 | vpsrad xmm4, xmm4, 6 // 0f1145c0 | vpsllq xmm4, xmm4, 0x34 // 0f104c2470 | and eax, ecx // 0f114dd0 | dec eax // 660f6f05???????? | $sequence_4 = { 418ac7 84c0 0f8408010000 8b4c2448 488d154240fdff 2b4c244c 41b826000000 } // n = 7, score = 100 // 418ac7 | dec eax // 84c0 | mov dword ptr [esp + 0x28], eax // 0f8408010000 | dec esp // 8b4c2448 | lea ecx, [esp + 0x60] // 488d154240fdff | dec eax // 2b4c244c | cmp dword ptr [esp + 0x78], 8 // 41b826000000 | dec esp $sequence_5 = { 488d4c2430 e8???????? 488d542430 488d4c2470 e8???????? 90 } // n = 6, score = 100 // 488d4c2430 | dec eax // e8???????? | // 488d542430 | sub esp, 0x20 // 488d4c2470 | dec esp // e8???????? | // 90 | mov esp, dword ptr [ecx + 0x18] $sequence_6 = { 488d4c2450 e8???????? 660f6f05???????? 488d152a670300 488d4de0 4c896de0 f30f7f45f0 } // n = 7, score = 100 // 488d4c2450 | cmp eax, esi // e8???????? | // 660f6f05???????? | // 488d152a670300 | jbe 0x7e4 // 488d4de0 | dec eax // 4c896de0 | mov ecx, 0xfffffffe // f30f7f45f0 | jmp 0x816 $sequence_7 = { 4183f805 0f8582000000 8b470c 458d487a c744243001000000 4c8d05ee7f0100 89442428 } // n = 7, score = 100 // 4183f805 | dec eax // 0f8582000000 | mov ecx, ebx // 8b470c | dec esp // 458d487a | lea edi, [0x372] // c744243001000000 | dec esp // 4c8d05ee7f0100 | mov dword ptr [esp + 0x20], edi // 89442428 | dec esp $sequence_8 = { ff15???????? 4c8be0 488985a0000000 488d15b9a30300 488bcb ff15???????? 4c8bf8 } // n = 7, score = 100 // ff15???????? | // 4c8be0 | dec eax // 488985a0000000 | lea eax, [0xffffee08] // 488d15b9a30300 | dec eax // 488bcb | mov dword ptr [esp + 0x20], eax // ff15???????? | // 4c8bf8 | dec esp $sequence_9 = { 488d4c2458 e8???????? 90 488d8d48010000 e8???????? 488d45a8 } // n = 6, score = 100 // 488d4c2458 | push edi // e8???????? | // 90 | dec eax // 488d8d48010000 | lea ebp, [esp - 0x5b8] // e8???????? | // 488d45a8 | dec eax condition: 7 of them and filesize < 652288 }
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