There is no lot of IOCs in this article so we take one sample and try to extract some interesting IOCs, our findings below :
CamuBot sample : 37ca2e37e1dc26d6b66ba041ed653dc8ee43e1db71a705df4546449dd7591479
Dropped Files on disk :
C:\Users\user~1\AppData\Local\Temp\protecao.exe : 0af612461174eedec813ce670ba35e74a9433361eacb3ceab6d79232a6fe13c1
C:\Users\user~1\AppData\Local\Temp\Renci.SshNet.dll : 3E3CD9E8D94FC45F811720F5E911B892A17EE00F971E498EAA8B5CAE44A6A8D8
C:\ProgramData\m.msi : AD90D4ADFED0BDCB2E56871B13CC7E857F64C906E2CF3283D30D6CFD24CD2190
Protecao.exe try to download hxxp://www.usb-over-network.com/usb-over-network-64bit.msi
A new driver is installed : C:\Windows\system32\drivers\ftusbload2.sys : 9255E8B64FB278BC5FFE5B8F70D68AF8
ftusbload2.sys set 28 IRP handlers.
rule win_camubot_auto { meta: author = "Felix Bilstein - yara-signator at cocacoding dot com" date = "2020-10-14" version = "1" description = "autogenerated rule brought to you by yara-signator" tool = "yara-signator v0.5.0" signator_config = "callsandjumps;datarefs;binvalue" malpedia_reference = "https://malpedia.caad.fkie.fraunhofer.de/details/win.camubot" malpedia_rule_date = "20201014" malpedia_hash = "a7e3bd57eaf12bf3ea29a863c041091ba3af9ac9" malpedia_version = "20201014" 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 = { 80bba002000000 7418 6a00 6a00 6807040000 8bc3 e8???????? } // n = 7, score = 100 // 80bba002000000 | cmp byte ptr [ebx + 0x2a0], 0 // 7418 | je 0x1a // 6a00 | push 0 // 6a00 | push 0 // 6807040000 | push 0x407 // 8bc3 | mov eax, ebx // e8???????? | $sequence_1 = { 3c22 3c26 3c42 3c65 3c8a 3cb8 3cc8 } // n = 7, score = 100 // 3c22 | cmp al, 0x22 // 3c26 | cmp al, 0x26 // 3c42 | cmp al, 0x42 // 3c65 | cmp al, 0x65 // 3c8a | cmp al, 0x8a // 3cb8 | cmp al, 0xb8 // 3cc8 | cmp al, 0xc8 $sequence_2 = { c745c8fc1d6000 c745c4ffffffff 33c0 33db 8945e4 8b45f8 8945fc } // n = 7, score = 100 // c745c8fc1d6000 | mov dword ptr [ebp - 0x38], 0x601dfc // c745c4ffffffff | mov dword ptr [ebp - 0x3c], 0xffffffff // 33c0 | xor eax, eax // 33db | xor ebx, ebx // 8945e4 | mov dword ptr [ebp - 0x1c], eax // 8b45f8 | mov eax, dword ptr [ebp - 8] // 8945fc | mov dword ptr [ebp - 4], eax $sequence_3 = { 0060af 47 007caf47 0088af4700a4 af 47 00b0af4700cc } // n = 7, score = 100 // 0060af | add byte ptr [eax - 0x51], ah // 47 | inc edi // 007caf47 | add byte ptr [edi + ebp*4 + 0x47], bh // 0088af4700a4 | add byte ptr [eax - 0x5bffb851], cl // af | scasd eax, dword ptr es:[edi] // 47 | inc edi // 00b0af4700cc | add byte ptr [eax - 0x33ffb851], dh $sequence_4 = { e9???????? 0100 0000 cc c9 41 0025???????? } // n = 7, score = 100 // e9???????? | // 0100 | add dword ptr [eax], eax // 0000 | add byte ptr [eax], al // cc | int3 // c9 | leave // 41 | inc ecx // 0025???????? | $sequence_5 = { 00f0 5f 47 000a 60 47 } // n = 6, score = 100 // 00f0 | add al, dh // 5f | pop edi // 47 | inc edi // 000a | add byte ptr [edx], cl // 60 | pushal // 47 | inc edi $sequence_6 = { 03148d1c526000 8b4814 0fb68960040000 294df4 } // n = 4, score = 100 // 03148d1c526000 | add edx, dword ptr [ecx*4 + 0x60521c] // 8b4814 | mov ecx, dword ptr [eax + 0x14] // 0fb68960040000 | movzx ecx, byte ptr [ecx + 0x460] // 294df4 | sub dword ptr [ebp - 0xc], ecx $sequence_7 = { 007c2d49 00962d4900b0 2d4900ca2d 49 00e4 2d4900fe2d } // n = 6, score = 100 // 007c2d49 | add byte ptr [ebp + ebp + 0x49], bh // 00962d4900b0 | add byte ptr [esi - 0x4fffb6d3], dl // 2d4900ca2d | sub eax, 0x2dca0049 // 49 | dec ecx // 00e4 | add ah, ah // 2d4900fe2d | sub eax, 0x2dfe0049 $sequence_8 = { 898e80000000 0fb70c8590116000 898e8c000000 0fb70c8594116000 898e90000000 } // n = 5, score = 100 // 898e80000000 | mov dword ptr [esi + 0x80], ecx // 0fb70c8590116000 | movzx ecx, word ptr [eax*4 + 0x601190] // 898e8c000000 | mov dword ptr [esi + 0x8c], ecx // 0fb70c8594116000 | movzx ecx, word ptr [eax*4 + 0x601194] // 898e90000000 | mov dword ptr [esi + 0x90], ecx $sequence_9 = { 0fb645fb 8b1c85e4516000 b806000000 8bd3 d1fa 7903 83d200 } // n = 7, score = 100 // 0fb645fb | movzx eax, byte ptr [ebp - 5] // 8b1c85e4516000 | mov ebx, dword ptr [eax*4 + 0x6051e4] // b806000000 | mov eax, 6 // 8bd3 | mov edx, ebx // d1fa | sar edx, 1 // 7903 | jns 5 // 83d200 | adc edx, 0 condition: 7 of them and filesize < 31375360 }
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