It has been reported that this issue has been dealt with, at least in part, by a vendor patch. This patch should be available through all Trend Micro distributors and retailers. Please see the referenced web site and contact the vendor for more information.
TrendMicro OfficeScan Corporate Edition (OSCE) contains a flaw that may allow a malicious local user to alter or disable anti-virus protection, due to insufficient permissions assigned the application's installation directory, files, and registry keys upon installation.
Currently, there are no known upgrades, patches, or workarounds available to completely correct this issue. It is reported the vendor has supplied a patch to resellers, "OSCE_Hotfix_RegistryTool.zip," which modifies the registry permissions, but the file permission issues remain unaddressed by the vendor.