HTML_IFRAME.AH is a heuristic detection for malicious HTML webpages and compromised computers through insertion of IFRAME tag.

Exploit-MSExcel.p is a heuristic detection to identify malware trying to exploit an unpatched vulnerability in Microsoft Excel.

Exploit-MS06-027 is a heuristic detection that covers files attempting to exploit a Microsoft Word buffer overflow vulnerability (MS06-027).

Exploit-MSWord.b is a heuristic detection to identify malformed Word Document files that attempts to exploit a new Microsoft Word vulnerability.

EXPL_PIDIEF.B is a detection for an exploit code that take advantage of the Adobe PDF Mailto vulnerability.

EXPL_PIDIEF.A is a proof-of-concept exploit code that takes advantage of unknown vulnerabilities in Adobe Acrobat software. It allows arbitrary code to execute on affected computers.

dungcoi_vb is not a virus, it is Yahoo Messenger visual basic script that promote certain user to be added as a friend.

Exploit-YWIDGET is a detection for Yahoo! Widgets YDPCTL ActiveX Control Buffer Overflow Vulnerability. 
The Buffer Overflow Vulnerability is in YDPCTL.dll ActiveX control of Yahoo widgets which can be exploited by malicious users to cause remote code execution.