Hackers frequently use RAR files to deliver "backdoor" programs or steal sensitive data once the user runs an enclosed file. Community Perspectives
“Any virus compressed in a RAR file can't harm your device until you extract it.” Avast · 2 years ago
If you have already downloaded the file, do not open it. Instead, upload it to the VirusTotal scanner to see if it triggers any security flags from major antivirus engines.
If the archive requires a password provided by a suspicious source, it is likely designed to bypass antivirus scans, as encrypted content cannot be easily inspected by security software. Technical Context