War-dialing is back, and it's not limited to finding modems anymore. Renowned researcher HD Moore is putting the final touches on his latest project -- a telephone auditing tool that also finds PBXes, dial tones, voicemail, faxes, and other phone line connections for security assessment, research, or inventory.
This is not your father's war-dialer: The so-called WarVOX is free, Linux-based software (no telephony hardware necessary) that uses voice over IP services to place calls. It looks at the audio in a call and is much faster than old-school war-dialing, scanning more than 1,000 phone numbers per hour over a residential broadband connection, and up to 10,000 in eight hours.
Moore says WarVOX is aimed at security auditors and penetration testers looking for a faster and cheaper way to detect phone system vulnerabilities. "Right now, the target audience for WarVOX is anyone who currently uses legacy war-dialing tools and is frustrated by the amount of time and money it takes to perform the audit," Moore says.
Traditional war-dialing has been on the decline in the broadband age. "Most security service providers that offer penetration tests still perform war-dialing for their clients. However, as a rule war-dialing has been a declining trend as fewer and fewer systems are left connected to modems," Moore says.
WarVOX, he says, is simple to use and can provide a wealth of security information for organizations looking at their phone-line security posture. PBX voice system lines, for example, can harbor security holes that could put an enterprise at risk. "After playing with WarVOX over the last few weeks, I was surprised at how many lines I have found that expose some sort of security risk," Moore says. "This includes the administrative interfaces to PBXes, lines that drop you to a fresh dial tone after a dozen rings, internal directories for large companies, and tons of sensitive information."
Moore hopes to release the new WarVOX 1.0.0 tonight if all goes well. The tool can detect voice, voicemail boxes, faxes, modems, dial tones, and even silence on a line. "The awesome thing about WarVOX is that while it can look for modems faster than any other tool on the market, it looks for much more than modems," he says. The next version of the tool will include grouping features, automatically assembling like-sounding numbers and supporting signatures that detect certain audio samples, he says.
WarVOX can also record audio on the other end of the line. "If the remote side of the line picks up, WarVOX will find it and record whatever audio happens to be there," Moore says. WarVOX can't yet emit a tone or try to elicit an audio response, but those features are in the works.
The tool can help gather data that can help glean sensitive information, such as the number of employees within a company, their names, and even layoff numbers -- all using phone responses. "It's possible to reverse-engineer a company directory out of the voice mail greetings," Moore says. "Company directory information is useful, but running WarVOX at regular intervals and viewing the data over time can provide a lot of useful data about an organization, such as how many people they laid off, how many new people they hired, and who is picking up their phone at a given time and date."
With the grouping feature in future versions of WarVOX, you can group lines by voicemail similarities, too, and earmark them for more manual review and testing, he says. If a group of lines in an organization don't have personal voicemail messages and sound different from other voicemail greetings, they could be forwarding lines to mobile phones, interactive voice response systems, or conference centers, for instance, he says.
WarVOX also records the audio and archives call data.
But there are legal issues with war-dialing, however. "War-dialing in the U.S. without permission is most likely illegal and should be avoided. Anyone interested in assessing their organization should make sure they have clear permission and understand how the two-party wiretapping statutes may apply to their assessment," Moore notes.
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Kelly Jackson Higgins is the Executive Editor of Dark Reading. She is an award-winning veteran technology and business journalist with more than two decades of experience in reporting and editing for various publications, including Network Computing, Secure Enterprise ... View Full Bio