Our web host suspended our sites due to a malicious file warning (see below). We received no warning from Wordfence. This occurred immediately after we did a recommended update last night to the Wordfence plugin (at about 11pm PT on August 28, 2012).
Malicious file(s) warning:
***/wp-content/plugins/wordfence/lib/wordfenceScanner.php => /usr/local/maldetect/quarantine/wordfenceScanner.php.25782
Not being very technically literate, as soon as they allowed us local access, I didn't know what else to do other than delete the entire plugin. (I tried to locate the problem files first, but no luck. ) Problem seems to be solved -- I've since confirmed with http://sitecheck.sucuri.net/scanner/ and I get the A-OK.