Actor(s): APT34
The primary function of LONGWATCH is a keylogger that outputs keystrokes to a log.txt file in the Windows temp folder.
rule win_longwatch_auto { meta: author = "Felix Bilstein - yara-signator at cocacoding dot com" date = "2026-01-05" version = "1" description = "Detects win.longwatch." 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.longwatch" 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 = { 83fb12 741e 83fb03 7419 } // n = 4, score = 200 // 83fb12 | cmp ebx, 0x12 // 741e | je 0x20 // 83fb03 | cmp ebx, 3 // 7419 | je 0x1b $sequence_1 = { 8b4004 c74410e8a0bb4200 8b42e8 8b4804 8d41e8 894411e4 } // n = 6, score = 200 // 8b4004 | mov eax, dword ptr [eax + 4] // c74410e8a0bb4200 | mov dword ptr [eax + edx - 0x18], 0x42bba0 // 8b42e8 | mov eax, dword ptr [edx - 0x18] // 8b4804 | mov ecx, dword ptr [eax + 4] // 8d41e8 | lea eax, [ecx - 0x18] // 894411e4 | mov dword ptr [ecx + edx - 0x1c], eax $sequence_2 = { 750b 8b0d???????? e8???????? e8???????? 83ec18 } // n = 5, score = 200 // 750b | jne 0xd // 8b0d???????? | // e8???????? | // e8???????? | // 83ec18 | sub esp, 0x18 $sequence_3 = { 8d8d48ffffff 68???????? e8???????? 85c0 8d8d30ffffff 8b8530ffffff } // n = 6, score = 200 // 8d8d48ffffff | lea ecx, [ebp - 0xb8] // 68???????? | // e8???????? | // 85c0 | test eax, eax // 8d8d30ffffff | lea ecx, [ebp - 0xd0] // 8b8530ffffff | mov eax, dword ptr [ebp - 0xd0] $sequence_4 = { 33f6 3bc8 740c 8b0cb5f8344200 46 } // n = 5, score = 200 // 33f6 | xor esi, esi // 3bc8 | cmp ecx, eax // 740c | je 0xe // 8b0cb5f8344200 | mov ecx, dword ptr [esi*4 + 0x4234f8] // 46 | inc esi $sequence_5 = { e8???????? 83ec14 c645fc02 8bcc 8bd0 51 } // n = 6, score = 200 // e8???????? | // 83ec14 | sub esp, 0x14 // c645fc02 | mov byte ptr [ebp - 4], 2 // 8bcc | mov ecx, esp // 8bd0 | mov edx, eax // 51 | push ecx $sequence_6 = { c705????????01000000 c705????????01000000 6a04 58 6bc000 8b4d08 898894004300 } // n = 7, score = 200 // c705????????01000000 | // c705????????01000000 | // 6a04 | push 4 // 58 | pop eax // 6bc000 | imul eax, eax, 0 // 8b4d08 | mov ecx, dword ptr [ebp + 8] // 898894004300 | mov dword ptr [eax + 0x430094], ecx $sequence_7 = { eb0f 8ad3 8d8d40ffffff e8???????? 8ad3 } // n = 5, score = 200 // eb0f | jmp 0x11 // 8ad3 | mov dl, bl // 8d8d40ffffff | lea ecx, [ebp - 0xc0] // e8???????? | // 8ad3 | mov dl, bl $sequence_8 = { 1bc0 83c801 85c0 745b e8???????? } // n = 5, score = 200 // 1bc0 | sbb eax, eax // 83c801 | or eax, 1 // 85c0 | test eax, eax // 745b | je 0x5d // e8???????? | $sequence_9 = { 8d8d48ffffff c78548ffffffdc334200 e8???????? 83ec08 c745fc02000000 } // n = 5, score = 200 // 8d8d48ffffff | lea ecx, [ebp - 0xb8] // c78548ffffffdc334200 | mov dword ptr [ebp - 0xb8], 0x4233dc // e8???????? | // 83ec08 | sub esp, 8 // c745fc02000000 | mov dword ptr [ebp - 4], 2 condition: 7 of them and filesize < 647168 }
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