AdwareMedic requires a Mac running Mac OS X 10.7 (Lion) or later.
AdwareMedic was a response to the growing sophistication of the adware developers that went beyond the capabilities of the author's
previous script. Unfortunately his previous script no longer works with today's generation of adware. Since you are using an out of date version of OS X your only option would be to go through all the steps you say are so complex or erase your HD and start over from scratch.
Adware of
DNSChanger Trojan ten comes packaged in installers for other software. Most often, this is because something was downloaded illegally from a torrent or piracy site. Sometimes it is because it has been added to a legit piece of software by an unscrupulous download site.
OK. What I've downloaded lately are: Skype and Open Office. I had to download Open Office to open a legitimate data file from a government website who (expletive deleted) put their data files up in open office format which these Macs could not open/read/use.
They were downloaded on Dec 2nd and Nov 24th respectively. So why did this thing pop up on Dec 15th?
Note the initial sentence, "
Adware often [emphasis added] comes packaged in installers for other software." It does not say. "Adware
always comes packaged in installers for other software." Adware distributors can and do learn lessons from virus distributors and it is not too surprising that they pick up some of their techniques. There is money to be made after all. For example look at how carefully the more recent versions of Genieo hide from detection and make themselves difficult to remove.
Assuming you got Skype from the publisher (Microsoft) at
www.skype.com and OpenOffice from
www.openoffice.org, both are reputable organizations and highly unlikely to be the source of your mystery download. It is far more likely the download originated from some link you clicked on while browsing the internet on a knowingly or unknowingly infected web site. More recent versions of OS X have more protection against this sort of thing, but that is not going to be available in an no longer supported version of OS X like 10.6.8.
By-the-way the file formats used by OpenOffice, NeoOffice, and LibreOffice on the Mac and PC are based on internationally accepted open standards unlike Microsoft's proprietary document standards. In fact Microsoft's .docx etc. formats are intentional corruptions of the the .odf standards used in the OpenOffice variants. More and more EU countries are moving toward open standards to get away from proprietary technologies.