Use a hex editor to see if the first few bytes are 52 61 72 21 (the standard RAR header). To provide a more detailed write-up, could you tell me:
Exploit-DB assigns numeric IDs to every entry. While "53612" isn't currently a public ID (most IDs are currently in the 51xxx range), this could be a placeholder or from a private repository. 53612.rar
Upload the file to VirusTotal to see if it matches known malware signatures. Use a hex editor to see if the
Some enterprise systems use .rar (Resource Adapter Archive) files to package connectors for Java EE applications. 53612.rar