I've done some research and thought a bit...

• The 2345 site is mentioned in several malware lists (including Microsoft, not just Kaspersky), associated with various trojans (or different names for the same one) such as Z2345. They install links to make your browser visit the site, though none of the descriptions make it clear whether the 2345 site itself contains malware.
• The malware may be a trick to drive traffic to the 2345 site to make its visitor statistics look good, which helps it with selling adverts (which is probably all it does: it appears to be a Chinese shopping site), so it may not be infecting your computer, but...
• Even if that site is harmless, every Mudcat page you load will be slowed down by having to download all that extra trash.
• The fact that Max's PC or web site has been infected means that there is a security problem which could result in other more dangerous infections.
• The replacement of a Google analytics script with something else is interfering with the effectiveness of Mudcat's Google adverts. Whether you like it or not, those ads are providing Max with a subsidy that enables the site to continue.