After studying the following log entries, how many user IDs can you identify that the attacker has tampered with?
1. mkdir -p /etc/X11/applnk/Internet/.etc
2. mkdir -p /etc/X11/applnk/Internet/.etcpasswd
3. touch -acmr /etc/passwd /etc/X11/applnk/Internet/.etcpasswd
4. touch -acmr /etc /etc/X11/applnk/Internet/.etc
5. passwd nobody -d
6. /usr/sbin/adduser dns -d/bin -u 0 -g 0 -s/bin/bash
7. passwd dns -d
8. touch -acmr /etc/X11/applnk/Internet/.etcpasswd /etc/passwd
9. touch -acmr /etc/X11/applnk/Internet/.etc /etc

A.
nobody, dns

B.
nobody, IUSR_

C.
IUSR_

D.
acmr, dns

Explanation:
Passwd is the command used to modify a user password and it has been used together with the usernames nobody and dns.