Overview
Ask users to tell you if any of the following suspicious activity occurs:
inability to log into Voice Mail
lost mail messages or altered greetings
inability to get an outside line
series of calls where there is silence on the other end or the caller
hangs up
sudden increase in wrong numbers
caller complaints that your lines are busy
callers claiming to represent the “phone” company. Ask for a callback
number.
callers trying to obtain sensitive information or asking for assistance in
placing outside or long-distance calls. Ask for a callback number.
increases in internal requests for assistance in making outside calls
(particularly international calls or requests for dial tone).
Make users with Outcalling privileges aware of the potential risks and
their responsibilities.
Never distribute the office telephone directory to anyone outside the
company.
Collect old office telephone directories and shred them.
Never discuss your telephone system’s numbering plan with anyone
outside your company.
Any time a call appears to be suspicious, call the Technical Service
Center at 1 800 628-2888 (in the U.S.).
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