There is no description at this point.
rule win_grabbot_auto { meta: author = "Felix Bilstein - yara-signator at cocacoding dot com" date = "2023-12-06" version = "1" description = "Detects win.grabbot." 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.grabbot" 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 = { 0fb702 83f85a 770b 83f841 7206 } // n = 5, score = 3300 // 0fb702 | movzx eax, word ptr [edx] // 83f85a | cmp eax, 0x5a // 770b | ja 0xd // 83f841 | cmp eax, 0x41 // 7206 | jb 8 $sequence_1 = { 83f85a 770d 83f841 7208 83c020 } // n = 5, score = 3300 // 83f85a | cmp eax, 0x5a // 770d | ja 0xf // 83f841 | cmp eax, 0x41 // 7208 | jb 0xa // 83c020 | add eax, 0x20 $sequence_2 = { 83f841 7206 83c020 0fb7c0 83c202 } // n = 5, score = 3300 // 83f841 | cmp eax, 0x41 // 7206 | jb 8 // 83c020 | add eax, 0x20 // 0fb7c0 | movzx eax, ax // 83c202 | add edx, 2 $sequence_3 = { ffd0 c3 b88dbdc13f 50 e8???????? } // n = 5, score = 3200 // ffd0 | call eax // c3 | ret // b88dbdc13f | mov eax, 0x3fc1bd8d // 50 | push eax // e8???????? | $sequence_4 = { ffe0 c3 c3 c3 68b9be7238 e8???????? 50 } // n = 7, score = 3200 // ffe0 | jmp eax // c3 | ret // c3 | ret // c3 | ret // 68b9be7238 | push 0x3872beb9 // e8???????? | // 50 | push eax $sequence_5 = { 03c7 813850450000 0f853c010000 0fb74804 ba4c010000 } // n = 5, score = 3200 // 03c7 | add eax, edi // 813850450000 | cmp dword ptr [eax], 0x4550 // 0f853c010000 | jne 0x142 // 0fb74804 | movzx ecx, word ptr [eax + 4] // ba4c010000 | mov edx, 0x14c $sequence_6 = { 03c3 813850450000 8945f8 7408 32c0 } // n = 5, score = 3200 // 03c3 | add eax, ebx // 813850450000 | cmp dword ptr [eax], 0x4550 // 8945f8 | mov dword ptr [ebp - 8], eax // 7408 | je 0xa // 32c0 | xor al, al $sequence_7 = { 7523 8b8c18a0000000 85c9 0f8489000000 837c187405 } // n = 5, score = 3200 // 7523 | jne 0x25 // 8b8c18a0000000 | mov ecx, dword ptr [eax + ebx + 0xa0] // 85c9 | test ecx, ecx // 0f8489000000 | je 0x8f // 837c187405 | cmp dword ptr [eax + ebx + 0x74], 5 $sequence_8 = { 56 ffd0 33c9 66894c37fe } // n = 4, score = 2600 // 56 | push esi // ffd0 | call eax // 33c9 | xor ecx, ecx // 66894c37fe | mov word ptr [edi + esi - 2], cx $sequence_9 = { 7428 8b0d???????? 8908 8b0d???????? 894804 } // n = 5, score = 2300 // 7428 | je 0x2a // 8b0d???????? | // 8908 | mov dword ptr [eax], ecx // 8b0d???????? | // 894804 | mov dword ptr [eax + 4], ecx $sequence_10 = { 89480c e9???????? 33c0 e9???????? } // n = 4, score = 2300 // 89480c | mov dword ptr [eax + 0xc], ecx // e9???????? | // 33c0 | xor eax, eax // e9???????? | $sequence_11 = { 894808 8b0d???????? 89480c e9???????? } // n = 4, score = 2300 // 894808 | mov dword ptr [eax + 8], ecx // 8b0d???????? | // 89480c | mov dword ptr [eax + 0xc], ecx // e9???????? | $sequence_12 = { 8bf0 85f6 741d 8d4601 50 e8???????? } // n = 6, score = 2000 // 8bf0 | mov esi, eax // 85f6 | test esi, esi // 741d | je 0x1f // 8d4601 | lea eax, [esi + 1] // 50 | push eax // e8???????? | $sequence_13 = { 85c0 56 0f9fc3 e8???????? 83c414 } // n = 5, score = 2000 // 85c0 | test eax, eax // 56 | push esi // 0f9fc3 | setg bl // e8???????? | // 83c414 | add esp, 0x14 $sequence_14 = { ff15???????? a3???????? 85c0 7505 83c8ff } // n = 5, score = 2000 // ff15???????? | // a3???????? | // 85c0 | test eax, eax // 7505 | jne 7 // 83c8ff | or eax, 0xffffffff $sequence_15 = { 741b 8d440002 50 e8???????? } // n = 4, score = 2000 // 741b | je 0x1d // 8d440002 | lea eax, [eax + eax + 2] // 50 | push eax // e8???????? | condition: 7 of them and filesize < 1335296 }
If your designated proposal does not fit in any other category, feel free to write a free-text in the comment field below. Changes regarding references should be proposed on the Malpedia library page.
Your suggestion will be reviewed before being published. Thank you for contributing!
YYYY-MM-DD
YYYY-MM
YYYY