undefined method JControllerLegacy::getInstance() - Joomla! Forum - community, help and support

folks, need help. i've built , maintain around 20 sites , problem happens 1 of them. @ loss why.

problem:
fatal error: call undefined method jcontrollerlegacy::getinstance() in /home/public_html/components/com_content/content.php on line 15

this site runs fine month. then, on own, no user interaction, breaks above error. far can tell logs, happened time on dec. 26 - not fired end of month.

what have done:
i have rebuilt site 4 times now. have changed template , even changed hosts. thing have not changed content. replacing core files brings site - issue remains.

questions:
1. think there script embedded in content somewhere causes error? hack?
2. have scoured through files , have found nothing out of ordinary. ideas on for?

any ideas welcome.

i believe found malicious file: .listing in directory, there several hundred of these. checked other installs using same components , modules, , did not see file - making unique site. through cpanel, search - not delete results en mass (as far know). so, did:

1. ran system restore date before error logs first post of call undefined method.
2. packaged existing files corrupted site , deleted files (but not new package of course)
3. extracted restored files , tested site. works fine.
4. downloaded restored file package mac , extracted it
5. because macs won't allow see files starting (.) had use terminal find .listing files in extracted folder. used:

code: select all

find path folder here -name ".listing"

6. sure search in restored files folder incase mac uses .listing file somewhere else.
7. after viewing results, added delete command:

code: select all

find path folder here -name ".listing" -delete

8. cleaned out .listing files. deleted files through cpanel except 2 archive packages.
9. compressed newly cleaned restore package (the 1 deleted .listing files from) , uploaded through cpanel.
10. extracted files, checked site , fine.
11. searched through cpanel .listing files , non exist.

so now, can out there me determine if there file or script creating .listing files? searched .htaccess files , found needed ones , clean of malicious code. searching through .php files take eternity. googled "common malicious file names" , didn't find needed.