Hi Greg,
Thanks for writing back.
Here is what they (Namecheap) said:
Subject: Attention: Malicious Attempt to Access Your Hosting Account
is DetectedThis is an automated alert to inform you that we have detected a malicious
attempt to access your account via http or ftp on our server
'server177.web-hosting.com'.
Our security systems have blocked the upload of malicious file to the server
and put it to the quarantine. Your website is safe now, but it is important
you undertake the following precautions. [and they named the usual stuff like changing passwords]We have put the following content into quarantine as we believe it contains
viruses or other malicious code.
'[PHP Exploit]':
/home/public_html/wp-content/plugins/wp-db-backup-made/sy
stem.php
'(decoded file [depth: 1])[Fingerprint Match]':
/home/public_html/wp-content/plugins/akismet/akismet.php
So when they did this the Akismet plugin vanished from my website's admin plugin page.
Consequently I can't look at the old akismet.php file on the server - cause it's gone.
Yesterday I downloaded WordPress v. 4.6 and changed my password again. That was the last fix that I know about and the hackers still got into my website this morning.
So, I will take your advice and contact the host to see if they know what might have been 'malicious' about the file.
Thanks for your help.
Tim