NTDLL Memory Protection Change via Unsigned DLL
Description
Identifies attempts to change memory protection of NTDLL from an unsigned final user module, this module is often targeted by malware for functions unhooking.
Query · eql
api where process.Ext.api.name == "VirtualProtect" and process.Ext.token.integrity_level_name != "low" and
process.Ext.api.metadata.target_address_name == "ntdll.dll" and
process.thread.Ext.call_stack_final_user_module.hash.sha256 != null and process.Ext.api.parameters.size > 4096 and
_arraysearch(process.thread.Ext.call_stack_final_user_module.code_signature, $entry, $entry.trusted == false or $entry.exists == false) and
not _arraysearch(process.thread.Ext.call_stack, $entry, $entry.symbol_info: ("*ntdll.dll!LdrLoadDll*", "*ntdll.dll!LdrUnloadDll*", "*ntdll.dll!LdrShutdownProcess*")) and
not process.thread.Ext.call_stack_final_user_module.path like
("?:\\program files\\*",
"?:\\program files (x86)\\*",
"?:\\windows\\assembly\\nativeimages_*",
"?:\\windows\\syswow64\\cyinjct.dll",
"?:\\windows\\system32\\tmumh\\*\\tmmon64.dll",
"?:\\windows\\winsxs\\*\\mfc??.dll") and
not process.thread.Ext.call_stack_final_hook_module.path like ("c:\\program files\\*", "c:\\program files (x86)\\*") and
not (process.Ext.api.parameters.size == 4096 and
_arraysearch(process.thread.Ext.call_stack, $entry, $entry.symbol_info: ("*chrome_elf.dll!GetInstallDetailsPayload*", "*chrome_elf.dll!DumpHungProcessWithPtype_ExportThunk*", "*mozglue.dll!??MAwakeTimeStamp*", "*firefox.exe!TargetNtUnmapViewOfSection*", "*firefox.exe!IsSandboxedProcess*"))) and
not process.thread.Ext.call_stack_final_user_module.protection_provenance_path like ("c:\\program files\\*", "c:\\program files (x86)\\*", "c:\\windows\\assembly\\nativeimages_*") and
not _arraysearch(process.thread.Ext.call_stack_final_user_module.code_signature, $entry,
$entry.trusted == true and $entry.subject_name in ("Carbon Black, Inc.", "MUSARUBRA US LLC", "Microsoft Windows Hardware Compatibility Publisher", "Kaspersky Lab JSC", "AO Kaspersky Lab", "Palo Alto Networks (Netherlands) B.V.", "G DATA CyberDefense AG")) and
not process.thread.Ext.call_stack_final_user_module.hash.sha256 in ("b27b7d2ac43c6c734aa9e370afc987704f4bd8ba11bc5199a8c3bc5b07b2600c",
"85f238fb7ace3cbdf7c29c72b01307c440f13491b07a509cbc5b9f257a637164",
"55f3206cf9bb092aef6a61508683144afe21ddf930686433bb233e2e233be38c",
"b152de9afc373bba831dc9c1b137668462ae6d46ccd46815f2ffcc7f1bfc7056",
"991042b4a0eb46fdfddb6f9118d046dc1ff500743ff01a8584ad5e73c092b188",
"7f6f5855d4968235163d75c62ab82e8fdc7cf3c83de34e3c5a0666e2d08a0001",
"b27b7d2ac43c6c734aa9e370afc987704f4bd8ba11bc5199a8c3bc5b07b2600c",
"ddcbecf2cd2cd4904cf21e3db40c6a918df0ed3b258473fc5d6e2688dee72696",
"18d1bae077da62bb5cf5bfa6a6c5c38ac9ade57f098ea2b357fab477e85f1c25",
"a0c662a21ba02f2b997907ad113097856916fc3683331e24d065e864213ff379",
"16f1b19c60f80ae33c5b4fef4acd38454f11bbc965dcdd622db0d1c5bb65b931",
"023983f43bb97fd6c909df5012c142140650eff6921a9b0db33c0f558402988d",
"01f46f2401df22465bf2b3f3d59343d14dcf6aada6747e386f1adb965af7b3c3",
"680dc9c393faad3851147bcbb3c5a1fd29b8ed61ddf1bf416f4415132d85f784",
"d59c12264054c84d5e988d4c340fe9d83d2f646f240b5fd52b9bf8564b0dd164",
"9becd39f90077a5ab064681c0a1be139d15be9ce434bacd48cd1dc894d3911cb",
"bb7b4184ea19f248c34f6fb670d37e3062f1648aacc98e009cec1a58c78e8871",
"8df8b4e86a9e96baa92bcd9cf1fca189565a90d815630df899d72ac6eefcf852",
"1902241e12adbdf40ed4dafc410ccbcf8e07fce117d540dabbc2f75ff371f5be",
"7117da40b5cd080575863842e2281576f9b6d1d41cb250690a13aef9cc6436c5",
"e06439cebb8280c46d0aa538ec89b4af4659e7f2915c5787b239871c9dfd65a5",
"f5f02a15419cbad6b0ea2eb9e986d25f13d23abf8e6b8b32ccf18e427f6c48aa",
"2496a1ad22ed1917037e5d6747e5401c50612cb0e3c9cf32a3a1233ebb53207c",
"4b0b5c6e06f7df6dd89dcb027200f6f86b7b4d7dc274a095a82bb609d8cdbe38",
"05b70f473543119cd831f9fc1cd2fbcdc7a3e1938c8a5cb208a2dda017433a7d",
"967189adfbc889fde89aafc867f7a1f02731f8592cf6fd5a4ace1929213e2e13",
"f216ea8efb5b3bb9ad3d938fb9ac07e3b8f78c2c92faab03d2c468d0b6798a5a",
"dea0369456f49fcb4fc5afa42fffb69ae1e19ea238d18e32d9c498d69ab12c69",
"4d40d7064907cf932abae04ef8864ca7288af6993e1ff9e958bd9ac756f62808",
"bfe6fd180245ec727fbc538b11ed59d714b3d794d4fadb2dc76d8a019422066a",
"90c2f3d2bceafb50fb4468bda7a68025f12a23673f151839cae56e2b1ce0a74d",
"3c3c4dcec5b68807e874455021a133b5f5945af86cb9149efed146065201039a",
"cb7ab3788d10940df874acd97b1821bbb5ee4a91f3eec11982bb5bf7a3c96443")