Can virus attacks computers by sharing a printer?

[Dewitt Roby]

Can virus attacks computers by sharing a printer?
I run a small business and had 2 computers in my office. I used one computer to do all the office work like keeping record & data, letters etc and the other which is connected to internet for email, research, etc. Both computers are sharing same printer. If the computer that connected to internet get attacked by a virus, does my other computer will be attacked too?

[DaveLembke]

Best protection is a good firewall between your systems and internet and daily virus update definitions and scans from a good antivirus, as well as daily or weekly data backups depending on how critical your data is to replace if wiped out. Most businesses go with daily backups minimum as well as shadow copying with MS Server and use of RAID 5 etc setups for protection against total data loss via infection or hardware damage and/or failure.

Is this printer a shared USB connected printer or a stand alone Network Printer in which the systems are both connecting to it as its own identity?  Shares and Pass thru authentication are your biggest concerns. Shares can allow for one system to spread the problem to the next. Pass Thru authentication can be a problem if the same user/password is valid on both systems, so as to where the infected system could call out to the next system and use same credentials to infect the next system.

It is VERY rare for a virus to spread via shared printer, but its not impossible. The most common points of entry are removable portable drives that connect between systems inside and outside of a business that can get infected and spread virus's, as well as e-mail attachments etc. Most creators of virus's go for the easier attacks like removable portable drives and e-mail attachments tying to get someone to unzip and execute or execute the attachment and then initiate the attack. They generally want it to spread more rampant and a shared printer if attacked in this method would probably stay within the systems of the shared network without looking for alternate paths of attack to worm out.

[Geek-9pm]

It is VERY rare for a virus to spread via shared printer, but its not impossible.

Yes, and it is more that just possible. It is doable if there is a great motivation. Otherwise, it is so much easier to make profit doing other kinds of malicious things. Of which, I know very little. 

Look here, Even if half of what hes says is true, it still presents t cause for paranoia.
9 ways your account can be compromised, even with a super-strong password.
He argues that it does not have to always be a hardware device that gets your. It can just be your habits and where and how you do your surfing on the net.