Actor(s): Tonto Team
There is no description at this point.
rule win_korlia_auto { meta: author = "Felix Bilstein - yara-signator at cocacoding dot com" date = "2020-08-17" version = "1" description = "autogenerated rule brought to you by yara-signator" tool = "yara-signator v0.4.0" tool_config = "callsandjumps;datarefs;binvalue" malpedia_reference = "https://malpedia.caad.fkie.fraunhofer.de/details/win.korlia" malpedia_rule_date = "20200817" malpedia_hash = "8c895fd01eccb47a6225bcb1a3ba53cbb98644c5" malpedia_version = "20200817" 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 / approach 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 = { 6a32 50 ff15???????? 85c0 } // n = 4, score = 2400 // 6a32 | push 0x32 // 50 | push eax // ff15???????? | // 85c0 | test eax, eax $sequence_1 = { b980ee3600 99 f7f9 b873b2e745 } // n = 4, score = 2200 // b980ee3600 | mov ecx, 0x36ee80 // 99 | cdq // f7f9 | idiv ecx // b873b2e745 | mov eax, 0x45e7b273 $sequence_2 = { 8bfa f7ef c1fa14 8bc2 c1e81f 03d0 } // n = 6, score = 2200 // 8bfa | mov edi, edx // f7ef | imul edi // c1fa14 | sar edx, 0x14 // 8bc2 | mov eax, edx // c1e81f | shr eax, 0x1f // 03d0 | add edx, eax $sequence_3 = { ffd6 8bc7 b980ee3600 99 } // n = 4, score = 2200 // ffd6 | call esi // 8bc7 | mov eax, edi // b980ee3600 | mov ecx, 0x36ee80 // 99 | cdq $sequence_4 = { 5a c745fcffffffff 8a45e4 8b4df0 64890d00000000 } // n = 5, score = 2200 // 5a | pop edx // c745fcffffffff | mov dword ptr [ebp - 4], 0xffffffff // 8a45e4 | mov al, byte ptr [ebp - 0x1c] // 8b4df0 | mov ecx, dword ptr [ebp - 0x10] // 64890d00000000 | mov dword ptr fs:[0], ecx $sequence_5 = { 6aff 53 6a00 6a00 ffd6 ff15???????? 8bf8 } // n = 7, score = 2200 // 6aff | push -1 // 53 | push ebx // 6a00 | push 0 // 6a00 | push 0 // ffd6 | call esi // ff15???????? | // 8bf8 | mov edi, eax $sequence_6 = { f2ae f7d1 49 83f90f 7604 } // n = 5, score = 2200 // f2ae | repne scasb al, byte ptr es:[edi] // f7d1 | not ecx // 49 | dec ecx // 83f90f | cmp ecx, 0xf // 7604 | jbe 6 $sequence_7 = { 8965e8 c645e401 c745fc00000000 52 51 } // n = 5, score = 2200 // 8965e8 | mov dword ptr [ebp - 0x18], esp // c645e401 | mov byte ptr [ebp - 0x1c], 1 // c745fc00000000 | mov dword ptr [ebp - 4], 0 // 52 | push edx // 51 | push ecx $sequence_8 = { 6a01 53 53 53 51 ff15???????? } // n = 6, score = 1900 // 6a01 | push 1 // 53 | push ebx // 53 | push ebx // 53 | push ebx // 51 | push ecx // ff15???????? | $sequence_9 = { e8???????? 83c410 85c0 7f14 } // n = 4, score = 1500 // e8???????? | // 83c410 | add esp, 0x10 // 85c0 | test eax, eax // 7f14 | jg 0x16 $sequence_10 = { 56 6a00 6a00 6a01 6a00 6a00 } // n = 6, score = 700 // 56 | push esi // 6a00 | push 0 // 6a00 | push 0 // 6a01 | push 1 // 6a00 | push 0 // 6a00 | push 0 $sequence_11 = { 6a01 6a00 6a00 6800000040 50 ff15???????? 8bf0 } // n = 7, score = 700 // 6a01 | push 1 // 6a00 | push 0 // 6a00 | push 0 // 6800000040 | push 0x40000000 // 50 | push eax // ff15???????? | // 8bf0 | mov esi, eax $sequence_12 = { 52 50 56 ff15???????? 56 ff15???????? b001 } // n = 7, score = 600 // 52 | push edx // 50 | push eax // 56 | push esi // ff15???????? | // 56 | push esi // ff15???????? | // b001 | mov al, 1 $sequence_13 = { ff15???????? 8bf0 83feff 7423 8b542410 } // n = 5, score = 600 // ff15???????? | // 8bf0 | mov esi, eax // 83feff | cmp esi, -1 // 7423 | je 0x25 // 8b542410 | mov edx, dword ptr [esp + 0x10] $sequence_14 = { 7423 8b542410 8b44240c 8d4c2408 } // n = 4, score = 600 // 7423 | je 0x25 // 8b542410 | mov edx, dword ptr [esp + 0x10] // 8b44240c | mov eax, dword ptr [esp + 0xc] // 8d4c2408 | lea ecx, [esp + 8] $sequence_15 = { f2ae f7d1 2bf9 6810270000 } // n = 4, score = 600 // f2ae | repne scasb al, byte ptr es:[edi] // f7d1 | not ecx // 2bf9 | sub edi, ecx // 6810270000 | push 0x2710 $sequence_16 = { 8bf9 81e7ff000000 03f2 03f7 } // n = 4, score = 500 // 8bf9 | mov edi, ecx // 81e7ff000000 | and edi, 0xff // 03f2 | add esi, edx // 03f7 | add esi, edi $sequence_17 = { 884814 8b4c240c 898840200000 58 c20800 e9???????? } // n = 6, score = 400 // 884814 | mov byte ptr [eax + 0x14], cl // 8b4c240c | mov ecx, dword ptr [esp + 0xc] // 898840200000 | mov dword ptr [eax + 0x2040], ecx // 58 | pop eax // c20800 | ret 8 // e9???????? | $sequence_18 = { c21000 e8???????? 8a4c2404 6a01 884814 } // n = 5, score = 400 // c21000 | ret 0x10 // e8???????? | // 8a4c2404 | mov cl, byte ptr [esp + 4] // 6a01 | push 1 // 884814 | mov byte ptr [eax + 0x14], cl $sequence_19 = { ff7588 ff15???????? 833d????????ff 750c ff742404 ff15???????? 59 } // n = 7, score = 400 // ff7588 | push dword ptr [ebp - 0x78] // ff15???????? | // 833d????????ff | // 750c | jne 0xe // ff742404 | push dword ptr [esp + 4] // ff15???????? | // 59 | pop ecx $sequence_20 = { 59 59 c3 8b65e8 ff7588 ff15???????? 833d????????ff } // n = 7, score = 400 // 59 | pop ecx // 59 | pop ecx // c3 | ret // 8b65e8 | mov esp, dword ptr [ebp - 0x18] // ff7588 | push dword ptr [ebp - 0x78] // ff15???????? | // 833d????????ff | $sequence_21 = { 5b 81c414040000 c3 56 } // n = 4, score = 400 // 5b | pop ebx // 81c414040000 | add esp, 0x414 // c3 | ret // 56 | push esi $sequence_22 = { 81ec08010000 8d442400 50 6806000200 6a00 68???????? } // n = 6, score = 300 // 81ec08010000 | sub esp, 0x108 // 8d442400 | lea eax, [esp] // 50 | push eax // 6806000200 | push 0x20006 // 6a00 | push 0 // 68???????? | $sequence_23 = { 6800040000 50 6a01 51 ff15???????? 85c0 7507 } // n = 7, score = 300 // 6800040000 | push 0x400 // 50 | push eax // 6a01 | push 1 // 51 | push ecx // ff15???????? | // 85c0 | test eax, eax // 7507 | jne 9 $sequence_24 = { 6a04 8b542414 51 81ca80010000 6a1f 56 } // n = 6, score = 300 // 6a04 | push 4 // 8b542414 | mov edx, dword ptr [esp + 0x14] // 51 | push ecx // 81ca80010000 | or edx, 0x180 // 6a1f | push 0x1f // 56 | push esi $sequence_25 = { 56 68ff0f1f00 ff15???????? 85c0 740a 56 50 } // n = 7, score = 300 // 56 | push esi // 68ff0f1f00 | push 0x1f0fff // ff15???????? | // 85c0 | test eax, eax // 740a | je 0xc // 56 | push esi // 50 | push eax $sequence_26 = { 8d4c2410 6804010000 51 aa ff15???????? bf???????? 83c9ff } // n = 7, score = 300 // 8d4c2410 | lea ecx, [esp + 0x10] // 6804010000 | push 0x104 // 51 | push ecx // aa | stosb byte ptr es:[edi], al // ff15???????? | // bf???????? | // 83c9ff | or ecx, 0xffffffff $sequence_27 = { 7403 50 ffd6 b912010000 } // n = 4, score = 300 // 7403 | je 5 // 50 | push eax // ffd6 | call esi // b912010000 | mov ecx, 0x112 $sequence_28 = { 8bc6 5f f7d8 1bc0 5e 24fe 5b } // n = 7, score = 300 // 8bc6 | mov eax, esi // 5f | pop edi // f7d8 | neg eax // 1bc0 | sbb eax, eax // 5e | pop esi // 24fe | and al, 0xfe // 5b | pop ebx $sequence_29 = { 68???????? 6801000080 ff15???????? 85c0 0f8599000000 53 } // n = 6, score = 300 // 68???????? | // 6801000080 | push 0x80000001 // ff15???????? | // 85c0 | test eax, eax // 0f8599000000 | jne 0x9f // 53 | push ebx $sequence_30 = { ffd6 8d44240c 6804010000 50 } // n = 4, score = 300 // ffd6 | call esi // 8d44240c | lea eax, [esp + 0xc] // 6804010000 | push 0x104 // 50 | push eax $sequence_31 = { 8bb424b0040000 51 8d9424a4000000 56 52 } // n = 5, score = 300 // 8bb424b0040000 | mov esi, dword ptr [esp + 0x4b0] // 51 | push ecx // 8d9424a4000000 | lea edx, [esp + 0xa4] // 56 | push esi // 52 | push edx $sequence_32 = { 83c408 8d4c241c 8d542420 6a00 } // n = 4, score = 300 // 83c408 | add esp, 8 // 8d4c241c | lea ecx, [esp + 0x1c] // 8d542420 | lea edx, [esp + 0x20] // 6a00 | push 0 $sequence_33 = { e8???????? 83c414 e8???????? 6a00 6a00 8d542414 } // n = 6, score = 300 // e8???????? | // 83c414 | add esp, 0x14 // e8???????? | // 6a00 | push 0 // 6a00 | push 0 // 8d542414 | lea edx, [esp + 0x14] $sequence_34 = { 56 3bc3 57 740b } // n = 4, score = 300 // 56 | push esi // 3bc3 | cmp eax, ebx // 57 | push edi // 740b | je 0xd $sequence_35 = { 8b35???????? 50 ffd6 eb06 8b35???????? a1???????? 3bc3 } // n = 7, score = 300 // 8b35???????? | // 50 | push eax // ffd6 | call esi // eb06 | jmp 8 // 8b35???????? | // a1???????? | // 3bc3 | cmp eax, ebx $sequence_36 = { ff15???????? 50 ff15???????? 68d0070000 ff15???????? } // n = 5, score = 300 // ff15???????? | // 50 | push eax // ff15???????? | // 68d0070000 | push 0x7d0 // ff15???????? | $sequence_37 = { 6a00 6a00 8d542414 6a00 52 68???????? } // n = 6, score = 300 // 6a00 | push 0 // 6a00 | push 0 // 8d542414 | lea edx, [esp + 0x14] // 6a00 | push 0 // 52 | push edx // 68???????? | $sequence_38 = { c745d8046f4000 e8???????? 683f000f00 57 57 } // n = 5, score = 100 // c745d8046f4000 | mov dword ptr [ebp - 0x28], 0x406f04 // e8???????? | // 683f000f00 | push 0xf003f // 57 | push edi // 57 | push edi $sequence_39 = { 50 c745ec02000080 ff15???????? 6a64 8d8dc4fdffff 68???????? } // n = 6, score = 100 // 50 | push eax // c745ec02000080 | mov dword ptr [ebp - 0x14], 0x80000002 // ff15???????? | // 6a64 | push 0x64 // 8d8dc4fdffff | lea ecx, [ebp - 0x23c] // 68???????? | condition: 7 of them and filesize < 163840 }
rule win_korlia_w0 { meta: author = "Nick Hoffman" company = "CBTS - ACS" information = "korlia malware found in apt dump" malpedia_reference = "https://malpedia.caad.fkie.fraunhofer.de/details/win.korlia" malpedia_version = "20180125" malpedia_license = "CC BY-NC-SA 4.0" malpedia_sharing = "TLP:WHITE" //case a //b2 1f mov dl, 0x1f ; mov key (wildcard) // ----------------- //8A 86 98 40 00 71 mov al, byte ptr url[esi] //BF 98 40 00 71 mov edi, offset url //32 C2 xor al, dl //83 C9 FF or ecx, 0FFFFFFFFh //88 86 98 40 00 71 mov byte ptr url[esi], al //33 C0 xor eax, eax //46 inc esi //F2 AE repne scasb //F7 D1 not ecx //49 dec ecx //3B F1 cmp esi, ecx //72 DE jb short loc_71001DE0 //case b (variant of loop a) //8A 8A 28 50 40 00 mov cl, byte_405028[edx] //BF 28 50 40 00 mov edi, offset byte_405028 //32 CB xor cl, bl //33 C0 xor eax, eax //88 8A 28 50 40 00 mov byte_405028[edx], cl //83 C9 FF or ecx, 0FFFFFFFFh //42 inc edx //F2 AE repne scasb //F7 D1 not ecx //49 dec ecx //3B D1 cmp edx, ecx //72 DE jb short loc_4047F2 //case c (not a variant of the above loop) //8A 0C 28 mov cl, [eax+ebp] //80 F1 28 xor cl, 28h //88 0C 28 mov [eax+ebp], cl //8B 4C 24 14 mov ecx, [esp+0D78h+var_D64] //40 inc eax //3B C1 cmp eax, ecx //7C EE jl short loc_404F1C strings: $a = {b2 ?? 8A 86 98 40 00 71 BF 98 40 00 71 32 c2 83 C9 FF 88 86 98 40 00 71 33 C0 46 F2 AE F7 D1 49 3B F1} $b = {B3 ?? ?? ?? 8A 8A 28 50 40 00 BF 28 50 40 00 32 CB 33 C0 88 8A 28 50 40 00 83 C9 FF 42 F2 AE F7 D1 49 3B D1} $c = {8A 0C 28 80 F1 ?? 88 0C 28 8B 4C 24 14 40 3B C1} $d = {00 62 69 73 6F 6E 61 6C 00} //config marker "\x00bisonal\x00" condition: any of them }
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