Should I block it?
No, this file is 100% safe to run.
 
     
    
        AUTHMGR.dll
Authentication Manager plugin for RealMedia (32-bit)
| Version:    | 10.0.1.1001 | 
| MD5:    | 44e8a68c61429248b4508d43fd9b99a9 | 
| SHA1:    | 4372971ad7b55072e414e99e32e9a497f69e2ed2 | 
| SHA256:    | cf8898fe888fedd77dd6cbb876d4c6c45cd4f41a284f27bb471cc05b56f334a0 | 
Overview
authmgr.dll is loaded as dynamic link library that runs in the context of a process. This particular version is usually found on Windows 8 Pro with Media Center (6.2.9200.0).
Details
| File name: | authmgr.dll | 
| Product name: | Authentication Manager plugin for RealMedia® (32-bit)  | 
| Description: | Authentication Manager plugin for RealMedia® | 
| Typical file path: | C:\Program Files\common files\real\plugins\authmgr.dll | 
| File version: | 10.0.1.1001 | 
| Size: | 44 KB (45,056 bytes) | 
| Digital DNA | 
| PE subsystem: | Windows GUI | 
| File packed: | No | 
| Code language: | Microsoft Visual C++ 7.1 | 
| .NET CLR: | No | 
More details
Distribution by Windows OS
| OS version | distribution | 
| Windows 8 Pro with Media Center | 
100.00% | 
 | 
Distribution by PC manufacturer
| PC Manufacturer | distribution | 
| GIGABYTE | 
100.00% | 
 |