The International Subversives

conquests in the underground, but each still had a competi- tive streak when it came to see who could get control over the system first. There was no ill will, just a little friendly competi- tion between mates.

Mendax poked around and realised the root directory, which contained the password file, was effectively world writable. This was good news, and with some quick manipulation he would be able to insert something into the root directory. On a more secure system, unprivileged users would not be able to do that. Mendax could also copy things from the directory on this site, and change the names of subdirectories within the main root directory. All these permissions were important, for they would enable him to create a Trojan.

Named for the Trojan horse which precipitated the fall of Troy, the Trojan is a favoured approach with most computer hackers. The hacker simply tricks a computer system or a user into thinking that a slightly altered file or directory – the Trojan – is the legitimate one. The Trojan directory, however, contains false information to fool the computer into doing something the hacker wants. Alternatively, the Trojan might simply trick a legitimate user into giving away valuable information, such as his user name and password.

Mendax made a new directory and copied the contents of the legitimate ETC directory – where the password files were stored – into it. The passwords were encrypted, so there wasn’t much sense trying to look at one since the hacker wouldn’t be able to read it. Instead, he selected a random legitimate user – call him Joe – and deleted his password. With no password, Mendax would be able to login as Joe without any problems.

However, Joe was just an average user. He didn’t have root, which is what Mendax wanted. But like every other user on the system, Joe had a user identity number. Mendax changed Joe’s user id to ‘0’ – the magic number. A user with ‘0’ as his id had root. Joe had just acquired power usually only given to system administrators. Of course, Mendax could have searched out a user on the list who already had root, but there were system