If the file is unusually small (a few KB), it likely contains a script or a shortcut designed to download further malware.

RAR files are often used to bypass email scanners. If the file is password-protected, it is even more likely to be malicious. j_dej.rar

Informative 13 * Informative 13. * External Systems. details 0/58 Antivirus vendors marked sample as malicious (0% detection rate) Hybrid Analysis 0001144204-12-064227.txt - SEC.gov If the file is unusually small (a few