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 = "2023-01-25" 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 = "20230124" malpedia_hash = "2ee0eebba83dce3d019a90519f2f972c0fcf9686" malpedia_version = "20230125" 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 = { 49c1fa06 4e8d1ced00000000 4d03dd 418a0438 41ffc1 4b8b8cd7f0940400 4903c8 } // n = 7, score = 100 // 49c1fa06 | dec esp // 4e8d1ced00000000 | lea ecx, [0x168d9] // 4d03dd | dec eax // 418a0438 | mov ebp, ecx // 41ffc1 | dec esp // 4b8b8cd7f0940400 | lea eax, [0x168c7] // 4903c8 | dec eax $sequence_1 = { 4c8bb5b0000000 e9???????? 488b4d28 e8???????? 90 488b4d38 } // n = 6, score = 100 // 4c8bb5b0000000 | inc edx // e9???????? | // 488b4d28 | test byte ptr [eax + ebp*8 + 0x38], 1 // e8???????? | // 90 | je 0x168 // 488b4d38 | dec eax $sequence_2 = { 0f45f8 897db0 89b578020000 4889742478 48897588 48897590 488d542458 } // n = 7, score = 100 // 0f45f8 | dec eax // 897db0 | mov edx, dword ptr [ebx] // 89b578020000 | dec eax // 4889742478 | shl edx, 4 // 48897588 | dec ebp // 48897590 | mov ecx, esi // 488d542458 | inc esp $sequence_3 = { 49635608 48035608 0fb60a 83e10f 4a0fbe840160280300 428a8c0170280300 482bd0 } // n = 7, score = 100 // 49635608 | push esi // 48035608 | inc ecx // 0fb60a | push edi // 83e10f | dec eax // 4a0fbe840160280300 | lea ebp, [esp - 0x1fc0] // 428a8c0170280300 | mov eax, 0x20c0 // 482bd0 | dec eax $sequence_4 = { 4885c9 7426 488d59f8 4d8bcc 4c8b03 498bd7 } // n = 6, score = 100 // 4885c9 | cmp eax, 0xc // 7426 | jb 0x29e // 488d59f8 | dec esp // 4d8bcc | mov ecx, edx // 4c8b03 | dec eax // 498bd7 | cmp dword ptr [edx + 0x18], 8 $sequence_5 = { 90 488b4dc0 e8???????? 90 488b4d90 e8???????? } // n = 6, score = 100 // 90 | dec esp // 488b4dc0 | mov esp, eax // e8???????? | // 90 | dec edx // 488b4d90 | cmp eax, dword ptr [ecx + edi*8 + 0x30] // e8???????? | $sequence_6 = { e8???????? 4883f8ff 743c 488b5c2450 48895c2440 488bcb e8???????? } // n = 7, score = 100 // e8???????? | // 4883f8ff | dec eax // 743c | mov ecx, dword ptr [ebp + 0x48] // 488b5c2450 | nop // 48895c2440 | dec eax // 488bcb | mov ecx, dword ptr [ebp - 0x18] // e8???????? | $sequence_7 = { 488b9c2460060000 4881c420060000 415f 415e 415d 415c 5f } // n = 7, score = 100 // 488b9c2460060000 | mov eax, dword ptr [esp + 0x68] // 4881c420060000 | test eax, eax // 415f | dec eax // 415e | lea edx, [esp + 0x70] // 415d | dec eax // 415c | lea ecx, [ebp + 0x1d0] // 5f | add ebx, edi $sequence_8 = { e8???????? 488bcb ff15???????? ffc0 4863c8 e8???????? 488bcb } // n = 7, score = 100 // e8???????? | // 488bcb | dec eax // ff15???????? | // ffc0 | mov esi, edi // 4863c8 | jb 0x267 // e8???????? | // 488bcb | dec eax $sequence_9 = { 488d15c1a30300 488bcb ff15???????? 488985a8000000 488b5710 48befeffffffffffff7f 488bce } // n = 7, score = 100 // 488d15c1a30300 | je 0x5a // 488bcb | dec esp // ff15???????? | // 488985a8000000 | mov dword ptr [edi + 0x68], esp // 488b5710 | jmp 0xa0 // 48befeffffffffffff7f | dec esp // 488bce | mov dword ptr [edi + 0x68], esi condition: 7 of them and filesize < 652288 }
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