Troj_Pandex.AG Trojan may be dropped by other malware. It may be downloaded unknowingly by a user when visiting malicious Web sites.

It drops a file also detected as TROJ_PANDEX.HG.

It attempts to login to certain mail servers. It connects to certain URLs to download possibly malicious files. It also uploads files to a certain URL via HTTP POST.

Technical details can be found at this Trend Micro page.