Posts Tagged: Mobile Number


5M+ harvested Russian mobile numbers service exposes fraudulent infrastructure

by

Cybercriminals continue adapting to the exponential penetration of mobile devices through the systematic release of DIY (do-it-yourself) mobile number harvesting tools, successfully setting up the foundations for commercial managed/on demand mobile phone number harvesting services, ultimately leading to an influx of mobile  malware/spam campaigns. In addition to boutique based DIY operations, sophisticated, ‘innovation’ and market development-oriented cybercriminals are actively working on the development of commercially available Android-based botnet generating tools, further fueling growth into the market segment. In a series of blog posts, we’ve been profiling multiple cybercrime-friendly services/malicious Android-based underground market releases, further highlighting the professionalization of the market […]

Continue Reading »

Fully automated, API-supporting service, undermines Facebook and Google’s ‘SMS/Mobile number activation’ account registration process

by

Operating in a world dominated by millions of malware-infected hosts acting as proxies for the facilitation of fraudulent and malicious activity, the Web’s most popular properties are constantly looking for ways to add additional layers of authentication to the account registration process of prospective users, in an attempt to undermine automatic account registration tactics. With CAPTCHA under automatic fire from newly emerging CAPTCHA solving/breaking services, re-positioning the concept from what was once the primary automatic account registration prevention mechanism, to just being a part of the ‘authentication mix’ these days, in recent years, a new (layered) authentication concept got the attention […]

Continue Reading »

Newly launched underground market service harvests mobile phone numbers on demand

by

In May of 2012, we highlighted the increasing public availability of managed SMS spam services that can send hundreds of thousands of SMS messages across multiple verticals. These services are assisted through the use of proprietary or publicly obtainable phone number harvesting and verifying DIY applications. In this post, I’ll profile one of the most recently advertised managed mobile phone number harvesting service which allows full customization of the harvesting criteria based on the specific requirements of the customer. More details:

Continue Reading »

DIY SIP-based TDoS tool/number validity checker offered for sale

by

By Dancho Danchev Over the past year, we observed an increase in publicly available managed TDoS (Telephony Denial of Service) services. We attribute this increase to the achieved ‘malicious economies of scale’ on behalf of the cybercriminals operating them, as well as the overall availability of proprietary/public DIY phone ring/SMS-based TDoS tools. What are cybercriminals up to in terms of TDoS attack tools? Let’s take a peek inside a recently released DIY SIP-based (Session Initiation Protocol) flood tool, which also has the capacity to validate any given set of phone numbers. More details:

Continue Reading »

DIY Russian mobile number harvesting tool spotted in the wild

by

By Dancho Danchev Earlier this year we profiled a newly released mobile/phone number harvesting application, a common tool in the arsenal of mobile spammers, as well as vendors of mobile spam services. Since the practice is an inseparable part of the mobile spamming process, cybercriminals continue periodically releasing new mobile number harvesting applications, update their features, but most interestingly, continue exclusively targeting Russian users. In this post, I’ll profile yet another DIY mobile number harvesting tool available on the underground marketplace since 2011, and emphasize on its most recent (2013) updated feature, namely, the use of proxies. More details:

Continue Reading »

How mobile spammers verify the validity of harvested phone numbers

by

Have you ever received a blank call, and no one was on the other side of the line? What about a similar blank SMS received through your mobile carrier’s Mail2SMS gateway? There’s a high probability that it was a mobile spammer who’s automatically and efficiently verifying the validity of a recently harvested database of mobile numbers, with QA (Quality Assurance) in mind. These verified databases will be later on used as the foundation for a highly successful spam/scam/malicious software disseminating campaigns, thanks to the fact that the cybercriminals behind them will no longer be shooting into the dark. How do they do […]

Continue Reading »