Actor(s): Equation Group
There is no description at this point.
rule win_grok_auto { meta: author = "Felix Bilstein - yara-signator at cocacoding dot com" date = "2022-05-16" version = "1" description = "Detects win.grok." 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.grok" malpedia_rule_date = "20220513" malpedia_hash = "7f4b2229e6ae614d86d74917f6d5b41890e62a26" malpedia_version = "20220516" 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 = { 8b95d8fdffff 8995d4fdffff 83bdd4fdffff00 0f8433030000 8d8538feffff 8985d0fdffff 8b4d14 } // n = 7, score = 400 // 8b95d8fdffff | mov edx, dword ptr [ebp - 0x228] // 8995d4fdffff | mov dword ptr [ebp - 0x22c], edx // 83bdd4fdffff00 | cmp dword ptr [ebp - 0x22c], 0 // 0f8433030000 | je 0x339 // 8d8538feffff | lea eax, [ebp - 0x1c8] // 8985d0fdffff | mov dword ptr [ebp - 0x230], eax // 8b4d14 | mov ecx, dword ptr [ebp + 0x14] $sequence_1 = { 8bfb 395dfc 0f8480000000 3bfb 747c a1???????? } // n = 6, score = 400 // 8bfb | mov edi, ebx // 395dfc | cmp dword ptr [ebp - 4], ebx // 0f8480000000 | je 0x86 // 3bfb | cmp edi, ebx // 747c | je 0x7e // a1???????? | $sequence_2 = { 5b 58 50 53 51 8b4d08 } // n = 6, score = 400 // 5b | pop ebx // 58 | pop eax // 50 | push eax // 53 | push ebx // 51 | push ecx // 8b4d08 | mov ecx, dword ptr [ebp + 8] $sequence_3 = { 6a0c eb1b 837d1002 eb0d 837d0c01 0f8584010000 395d10 } // n = 7, score = 400 // 6a0c | push 0xc // eb1b | jmp 0x1d // 837d1002 | cmp dword ptr [ebp + 0x10], 2 // eb0d | jmp 0xf // 837d0c01 | cmp dword ptr [ebp + 0xc], 1 // 0f8584010000 | jne 0x18a // 395d10 | cmp dword ptr [ebp + 0x10], ebx $sequence_4 = { 8b4304 a801 0f84a6000000 8b03 3bc7 0f8497000000 0f8ec7000000 } // n = 7, score = 400 // 8b4304 | mov eax, dword ptr [ebx + 4] // a801 | test al, 1 // 0f84a6000000 | je 0xac // 8b03 | mov eax, dword ptr [ebx] // 3bc7 | cmp eax, edi // 0f8497000000 | je 0x9d // 0f8ec7000000 | jle 0xcd $sequence_5 = { 8b55fc 66833c425c 7506 41 3b4dec 7408 40 } // n = 7, score = 400 // 8b55fc | mov edx, dword ptr [ebp - 4] // 66833c425c | cmp word ptr [edx + eax*2], 0x5c // 7506 | jne 8 // 41 | inc ecx // 3b4dec | cmp ecx, dword ptr [ebp - 0x14] // 7408 | je 0xa // 40 | inc eax $sequence_6 = { 0f8466010000 837d0c00 0f845c010000 837d1400 0f8452010000 56 ff15???????? } // n = 7, score = 400 // 0f8466010000 | je 0x16c // 837d0c00 | cmp dword ptr [ebp + 0xc], 0 // 0f845c010000 | je 0x162 // 837d1400 | cmp dword ptr [ebp + 0x14], 0 // 0f8452010000 | je 0x158 // 56 | push esi // ff15???????? | $sequence_7 = { 895df0 66895ddc 66895dde 895de0 ffd6 8b3d???????? 8d45dc } // n = 7, score = 400 // 895df0 | mov dword ptr [ebp - 0x10], ebx // 66895ddc | mov word ptr [ebp - 0x24], bx // 66895dde | mov word ptr [ebp - 0x22], bx // 895de0 | mov dword ptr [ebp - 0x20], ebx // ffd6 | call esi // 8b3d???????? | // 8d45dc | lea eax, [ebp - 0x24] $sequence_8 = { 33ff 47 3bc3 8945fc 0f8c9c000000 391d???????? 7410 } // n = 7, score = 400 // 33ff | xor edi, edi // 47 | inc edi // 3bc3 | cmp eax, ebx // 8945fc | mov dword ptr [ebp - 4], eax // 0f8c9c000000 | jl 0xa2 // 391d???????? | // 7410 | je 0x12 $sequence_9 = { 8b4508 8b08 894dfc 8b55fc 0fb702 3dff250000 755a } // n = 7, score = 400 // 8b4508 | mov eax, dword ptr [ebp + 8] // 8b08 | mov ecx, dword ptr [eax] // 894dfc | mov dword ptr [ebp - 4], ecx // 8b55fc | mov edx, dword ptr [ebp - 4] // 0fb702 | movzx eax, word ptr [edx] // 3dff250000 | cmp eax, 0x25ff // 755a | jne 0x5c condition: 7 of them and filesize < 84992 }
rule win_grok_w0 { meta: author = "Kaspersky Lab" copyright = "Kaspersky Lab" description = "Rule to detect the crypto library used in Equation group malware" version = "1.0" last_modified = "2015-02-16" reference = "https://securelist.com/blog/" source = "https://github.com/mattulm/sfiles_yara/blob/master/malware/Equation.yar" malpedia_reference = "https://malpedia.caad.fkie.fraunhofer.de/details/win.grok" malpedia_version = "20170517" malpedia_sharing = "TLP:WHITE" malpedia_license = "" strings: $a={37 DF E8 B6 C7 9C 0B AE 91 EF F0 3B 90 C6 80 85 5D 19 4B 45 44 12 3C E2 0D 5C 1C 7B C4 FF D6 05 17 14 4F 03 74 1E 41 DA 8F 7D DE 7E 99 F1 35 AC B8 46 93 CE 23 82 07 EB 2B D4 72 71 40 F3 B0 F7 78 D7 4C D1 55 1A 39 83 18 FA E1 9A 56 B1 96 AB A6 30 C5 5F BE 0C 50 C1} condition: $a }
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