– trojans (also called backdoors): the program part (server) installed on victim pc communicates with the program part (client) on pseudo-hacker pc via internet ports (TCP/UDP). The hacker can just not only stole pc victim’s data but he can also take command of the pc (a kind of remote control) and do everything as these programs are so powerful
– keyloggers: program that once installed on victim pc records any keyboard activity and sends these info in silent mode to “pseudo-hacker” pc
– programs to spy specific info of victim pc: for example info from browser, IM, etc… also these sends info in silent mode to “pseudo-hacker” pc
If you have a good protection system you have good chance to intercept these programs.
So often the pseudo-hacker use other programs that crypt using particular algorithms the program that will send to victim pc.
As written then the pseudo-hacker use other programs to hide the malware program inside a “normal” file (image, mp3, etc…) to don’t let the victim pc user notice about it.
I also said that some of these programs send in silent way the info to “pseudo-hacker” pc, mainly it’s done in 3 ways:
– a mail server will be installed too on victim pc, so the info will then be sent by email
– via ftp: info will be stored in a server ftp that pseudo-hacker know
– via web: info are sent to a web page known from pseudo-hacker within server side technologies (asp, php)
Some programs are advanced and have extra features: for example stealth feature; the programs result invisible not only to anti malware but for example also on system processes, or they can record audio/voice conversations and video from webcam.
The “serious hacker” has more deep knowledge; he doesn’t use (and don’t need) these programs to stole data from victim pc but he study the target os and he tries to understand and discover software vulnerabilities, often he writes custom programs by himself to take advantages of these vulnerabilities.
How to protect yourself?
The suggestions are to be protected by very good anti malware systems, keep system and software up to date, think well first when you receive a file!
