From
Trend MicroLike the earlier BROPIA variants, this memory-resident worm spreads copies of itself via MSN messenger, a popular instant messaging application, using attractive file names.
This worm arrives as a Win32 .EXE file. Upon execution, this non-encrypted, memory-resident worm drops another file which Trend Micro detects as WORM_RBOT.AOR.
The dropped file can have the filename WINIS.EXE. Its attributes are set to hidden, system and read-only. After dropping, WORM_BROPIA.S executes this file.
It drops a JPEG picture file in the root folder, which is usually C:\. It opens the image with Internet Explorer (IE). The following is a sample of the dropped image file:
http://www.trendmicro.com/vinfo/images/WORM_BROPIA_S_img1.gifIt also sets the attributes of this dropped file to read-only, hidden and system to avoid easy detection. After dropping, it executes this file and terminates itself.
The worm propagates using MSN Messenger, a popular chat program. It sends its copy to all contacts found in the MSN Messenger application.
It arrives via MSN Messenger with a message that contains the following details:
(message)(link)
======================================================
(message) can be any of the following:
• CHECK THIS LOL!
• CUSTOM
• Huge Turd hahaah! :-P
• LOOK! :-O
• nice! :-P
• ownage! 
• paris hilton got hacked!! 
(link) can be any of the following:
• http://members.chello.nl/a.sinnema1/FUNNY-SHIT!.pif
• http://members.chello.nl/a.sinnema1/scary.pif
• http://members.chello.nl/a.sinnema1/sexy-bitch.pif
• http://members.chello.nl/h.keuth/massive-turd.pif
• http://members.chello.nl/h.keuth/paris-hilton.pif
• http://members.chello.nl/h.keuth/w00t!.pif
Since it's being detected as an Rbot, it will be deemed as dangerous.
Rbot is a backdoor trojan, meaning it will open your computer to attacks by hackers. The recommended solution is to reformat, to prevent loss of sensitive information.
Also, it is to save you from getting you into trouble with laws. This trojan can connect you to some dubious websites and launch attacks against websites, known as DDoS, which is illegal.