There are several ways that criminals can use your voicemail to make calls. First, through your voicemail, a criminal is able to use your PBX “trunk-to-trunk connections” feature to access your long distance network. Secondly, your voicemail might also be used as a “bulletin-board” to distribute stolen credit card and other information that criminals would be interested in. Thirdly, they may change your greeting to “Hello…(pause)…Yes, I’ll accept the charges to (insert country name.”