There is a file named
aescn.dylib, which is part of Avira Free Mac Security, but I don't know if the hash you quoted coincides with that of the legitimate file. You can find the SHA256 of that file by submitting the link to download the specific version of Avira (from the Avira website) to VirusTotal, and clicking on aescn.dylib under the "Contained files" section of the downloaded file analysis.
If it coincides, it might be a false positive (only TrendMicro detects it as malware), but since Avira is free, you can go the safe way and install it again, or even install other antimalware solutions.
If not, it could be that your version of Avira is actually a rogue antivirus, and thus malicious. In this case, you should definitely uninstall it, and it would probably be not enough. When you install an AV, you give it a lot of permissions, which means that a rogue antivirus could have done a lot of things to your system. The safest way would, unfortunately, to perform a clean install of Mac OS (or another operating system), or even to buy a new computer.