CF 8,0,0,176276 Jrun downloading malware, will update of hotfix help?

It will help, but it will probably not solve your problem. CF8 is an end of life product, so it does not have all possible security hotfixes available. The most critical omission for CF8 is the APSB13-03 patch which has been exploited quite a bit over the last 4-5 months.   Your best course of action is to ditch the server and do a fresh install of CF9 or 10 apply all security hotfixes and follow the lockdown guides for CF9 or CF10.

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Pete Freitag

Foundeo Inc, makers of HackMyCF and FuseGuard