Actor(s): Leviathan
BADFLICK, a backdoor that is capable of modifying the file system, generating a reverse shell, and modifying its command-and-control configuration.
rule win_badflick_auto { meta: author = "Felix Bilstein - yara-signator at cocacoding dot com" date = "2026-01-05" version = "1" description = "Detects win.badflick." 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.badflick" 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 = { 8bd8 ff37 ff15???????? 50 e8???????? 50 ff7508 } // n = 7, score = 100 // 8bd8 | mov ebx, eax // ff37 | push dword ptr [edi] // ff15???????? | // 50 | push eax // e8???????? | // 50 | push eax // ff7508 | push dword ptr [ebp + 8] $sequence_1 = { ff35???????? ff750c ff75fc ff33 e8???????? 8b7d10 83c418 } // n = 7, score = 100 // ff35???????? | // ff750c | push dword ptr [ebp + 0xc] // ff75fc | push dword ptr [ebp - 4] // ff33 | push dword ptr [ebx] // e8???????? | // 8b7d10 | mov edi, dword ptr [ebp + 0x10] // 83c418 | add esp, 0x18 $sequence_2 = { 55 8bec ff7508 6a2b } // n = 4, score = 100 // 55 | push ebp // 8bec | mov ebp, esp // ff7508 | push dword ptr [ebp + 8] // 6a2b | push 0x2b $sequence_3 = { 807d1000 59 5f 5e } // n = 4, score = 100 // 807d1000 | cmp byte ptr [ebp + 0x10], 0 // 59 | pop ecx // 5f | pop edi // 5e | pop esi $sequence_4 = { be00f00000 56 e8???????? 59 53 8d4df8 51 } // n = 7, score = 100 // be00f00000 | mov esi, 0xf000 // 56 | push esi // e8???????? | // 59 | pop ecx // 53 | push ebx // 8d4df8 | lea ecx, [ebp - 8] // 51 | push ecx $sequence_5 = { 8b4904 03c8 81f9fe34012c 7509 83f805 } // n = 5, score = 100 // 8b4904 | mov ecx, dword ptr [ecx + 4] // 03c8 | add ecx, eax // 81f9fe34012c | cmp ecx, 0x2c0134fe // 7509 | jne 0xb // 83f805 | cmp eax, 5 $sequence_6 = { 6a3d e8???????? 8bf0 8a4508 59 59 884605 } // n = 7, score = 100 // 6a3d | push 0x3d // e8???????? | // 8bf0 | mov esi, eax // 8a4508 | mov al, byte ptr [ebp + 8] // 59 | pop ecx // 59 | pop ecx // 884605 | mov byte ptr [esi + 5], al $sequence_7 = { a5 a5 eb02 33c0 50 6a00 } // n = 6, score = 100 // a5 | movsd dword ptr es:[edi], dword ptr [esi] // a5 | movsd dword ptr es:[edi], dword ptr [esi] // eb02 | jmp 4 // 33c0 | xor eax, eax // 50 | push eax // 6a00 | push 0 $sequence_8 = { 8d8548f3ffff 50 ffd7 8d856cf9ffff 50 8d8560f7ffff } // n = 6, score = 100 // 8d8548f3ffff | lea eax, [ebp - 0xcb8] // 50 | push eax // ffd7 | call edi // 8d856cf9ffff | lea eax, [ebp - 0x694] // 50 | push eax // 8d8560f7ffff | lea eax, [ebp - 0x8a0] $sequence_9 = { a5 a5 e8???????? 59 6a00 } // n = 5, score = 100 // a5 | movsd dword ptr es:[edi], dword ptr [esi] // a5 | movsd dword ptr es:[edi], dword ptr [esi] // e8???????? | // 59 | pop ecx // 6a00 | push 0 condition: 7 of them and filesize < 81920 }
rule win_badflick_w0 { meta: description = "Detects BADFLICK backdoor" author = "@VK_Intel" reference = "BADFLICK backdoor" date = "2018-03-26" hash = "7ba05abdf8f0323aa30c3d52e22df951eb5b67a2620014336eab7907b0a5cedf" reference = "https://www.fireeye.com/blog/threat-research/2018/03/suspected-chinese-espionage-group-targeting-maritime-and-engineering-industries.html" malpedia_reference = "https://malpedia.caad.fkie.fraunhofer.de/details/win.badflick" malpedia_version = "20180407" malpedia_license = "CC BY-NC-SA 4.0" malpedia_sharing = "TLP:WHITE" strings: $s0 = "%s\\en-US\\cmd.exe.mui" fullword wide $s1 = "[Green] pid=%d tid=%d modulePath=%s|" fullword wide $s2 = "1|103.243.175.181|80|5|xxxxxxxxxxxxxxxxxxxxxxx" wide ascii $s3 = "modulePath=%[^|]" fullword wide $s4 = "%s:%d:%s:%d:%d" fullword ascii $s5 = "regsvr32 %s %s %s go \"%s\"" fullword wide $s6 = "modulePath=" fullword wide $s7 = "%d %d.%d.%d %s" fullword wide $s8 = "winMain static green" fullword wide $s9 = "o%d Core %.2f GHz" fullword wide $s10 = "6&62676=6B6G6N6c6s6" fullword ascii $op0 = { 8b 54 24 54 8b cf 2b cb 8d 04 0a 3b c7 76 02 8b } $op1 = { a1 08 77 40 00 89 45 94 8d 45 94 50 ff 35 04 77 } $op2 = { 8b 7c 24 14 8b f7 2b f5 8d 64 24 00 8a 1f 84 db } condition: uint16(0) == 0x5a4d and filesize < 108KB and 8 of ($s*) and 1 of ($op*) }
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