Instruction manual

Known toll fraud activity
Issue 9 May 2003
2-5
— Voice mail
There are two types of voice mail fraud. The first type, which is
responsible for the bulk of equipment-related toll fraud loss, relies on
misuse of the call transfer capabilities of voice mail systems. Once
thieves transfer to dial tone, they may dial a Trunk Access Code
(TAC), Feature Access Code or Facility Access Code (FAC), or
extension number.
If the system is not properly secured, thieves can make fraudulent
long distance calls or request a company employee to transfer them
to a long distance number.
The second type of voice mail fraud occurs when a hacker accesses
a mailbox to either take it over or simply access the information
stored within it.
In the first situation, a hacker dials either 9 or a TAC that allows the
call to be transferred to the outgoing facilities. In the second
situation, a hacker typically hacks the mail password and changes it
along with the greeting. This gives the hacker access to proprietary
corporate information.
—
Automated attendant
Auto attendants are used by many companies to augment or
replace a switchboard operator. When an automated attendant
answers, the caller is generally given several options. A typical
greeting is: “Hello, you’ve reached XYZ Bank. Please enter
1 for
Auto Loans,
2 for Home Mortgages. If you know the number of the
person you are calling, please enter that now.”
In some Auto Attendants, option 9 is to access dial tone. In addition,
when asked to enter an extension, the hacker enters 9180 or 9011.
If the system is not properly configured, the automated attendant
passes the call back to the PBX. The PBX reacts to 9 as a request
for a dial tone. The 180 becomes the first numbers of a 1-809 call to
the Dominican Republic. The 011 is treated as the first digits of an
international call. The hacker then enters the remaining digits of the
phone number and the call is completed. You, the PBX owner, pay
for it. This hacker scenario works the same way with a voice mail
system.
—
Remote access/direct inward system access (DISA)
Remote access or DISA is designed to allow remote users to access
a PBX to place long distance calls as if they were at the same site
as the PBX. Because of the potential cost savings, many PBX
owners use DISA instead of calling cards; however, remote access
capability opens the door for fraudulent calls by thieves.
Hackers are able to locate the DISA feature with the use of a war
dialer, explained previously. After finding a number, the device
searches for barrier codes.