Malware running from Dropbox. Must be some flaw in the software that allows that. FYI - PM me before posting such a large log like this last Gmer log.
See if you can uninstall Dropbox. Reboot after, and just update me if the uninstall went without a problem.
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But also go here and download Malwarebytes AntiRootkit from
here to your desktop, then click that and allow it to extract to your desktop.
Click Next, then click the Update button (you will need to have the Internet connected for this). Once it has updated, click Next, then click Scan.
When it finishes, click Exit. Then post the two logs it created, located in the same mbar folder on your desktop.
mbar-log-date-(xx-xx-xx).txt
system-log.txt