Dark Reading is part of the Informa Tech Division of Informa PLC

This site is operated by a business or businesses owned by Informa PLC and all copyright resides with them.Informa PLC's registered office is 5 Howick Place, London SW1P 1WG. Registered in England and Wales. Number 8860726.

Risk

10/5/2018
02:30 PM
Connect Directly
Twitter
LinkedIn
Google+
RSS
E-Mail
50%
50%

Successful Scammers Call After Lunch

Analysis of 20,000 voice phishing, or vishing, calls reveals patterns in how social engineers operate and how targets respond.

Voice phishing scams are most successful in the afternoon and least effective on Mondays, according to an analysis of thousands of these "vishing" calls over a three-year time frame.

Chris Hadnagy, founder and CEO of Social-Engineer, and Cat Murdock, a social engineer and pen tester at the company, had the idea to record vishing calls back in 2015. More than 20,000 calls later, they decided to compile the data they collected into a single report. Today, the duo took the stage today at DerbyCon to present their findings.

"Outside of malicious scam organizations, we may be one of the largest vishing centers in the world for social engineering professionals," said Hadnagy, in an interview with Dark Reading.

Of the 20,144 total calls made, 5,690 were completed, meaning the social engineer spoke with someone on the other end of the line. Of the completed calls, agents had a total of 3,017 compromises, a success ratio of 53%. Less than half (45.3%) of the calls resulted in a "shutdown," meaning they weren't able to get the minimum amount of data from their target.

Their calls dug up a total of 8,685 "flags," or pieces of information they had to obtain from their targets. This ranged from Social Security numbers, which they were able to learn 15.6% of the time, to information on internal projects (9.48%), to answers to security questions (1.1%).

Following are the key trends and takeaways from years of vishing data.

Mondays Are The Worst
An obvious statement, to be fair, but one that very much applies to vishing calls. Monday is the day you're most likely to get someone on the phone – but the least likely to compromise them.

"Monday is a really interesting outlier," Murdock said. The first day of the workweek has a compromise ratio of 29%, which is very low compared with Tuesday (62%), Wednesday (63%), Thursday (58%), and Friday (65%). People are most likely to answer the phone on Monday, which is also the day with the lowest voicemail ratio (60%) and shutdown ratio (70%).

Hadnagy, who admitted he doesn't know the targets' exact reasoning, put himself in their shoes.

"Monday, I just got back from the weekend, I'm refreshed, I'm ready to rock and roll," he said. "By the time Friday hits, I've been battered like an egg in a pan, and now I just wanna give up and go back to the weekend." What's more, he continued, people are more likely to take Fridays off for long weekends. Few folks take vacation on Mondays, so most people are in the office.

Drilling down into specific times of day, vishing calls are more successful the later it gets. Afternoon seems to be the best time, Murdock said, citing the 65% average compromise ratio.

When people arrive to their desks in the morning, the rate of compromise is lower. They're alert, they're focused, and they're less likely to share sensitive information. Later in the day, the compromise ratio increases, hitting its peak just as employees are getting ready to leave.

"Highest is at 5 p.m.," Murdock told Dark Reading. "People who are potentially working a little bit late and they're really ready [to leave, they'll] tell you what you need to get you off the phone."

Is That Call Really From HR?
The analysis also touched on the pretext, or the social engineer's strategy, for convincing their targets they were legitimate. More than three-quarters (76%) of agents pretended to work with facilities, 74% said they were calling as part of their work with a training department, 72% claimed to have lost the organization's address, and 63% pretended to be calling HR.

Impersonation, a tactic in which social engineers research a specific person and pretend to be that person to elicit information, is the most difficult technique to pull off, Murdock noted.

"It's one of our most challenging pretexts," she said. "You have to really know that person."

Hadnagy and Murdock divide the most common pretexts into two themes. One is HR, which encompasses vishing calls related to healthcare, databases, financial questions, open enrollment, portals, training, and wellness. The second was IT, where pretexts relate to audits, badges, databases, security, updates, and VoIP.

Yes, both categories include database-related questions. However, HR-related database calls had a higher compromise ratio (28%) than IT (21% compromise). Open enrollment vishing calls were the most effective, with a 100% compromise ratio. If you're looking to capture key data from HR, a well-timed open enrollment angle could be effective.

Women Are Winning
"Women just do better at social engineering," says Hadnagy, citing the data showing how female social engineers typically outperform males regardless of the target's gender.

This finding applies across all pretexts the team studied, meaning women were more successful in obtaining key information, whether they pretended to be an employee of the target company, a reporter, a facilities worker, IT personnel, or a training manager. The only area in which men were more effective than women was in calling with questions related to a conference.

Related Content:

 

Black Hat Europe returns to London Dec 3-6 2018  with hands-on technical Trainings, cutting-edge Briefings, Arsenal open-source tool demonstrations, top-tier security solutions and service providers in the Business Hall. Click for information on the conference and to register.

Kelly Sheridan is the Staff Editor at Dark Reading, where she focuses on cybersecurity news and analysis. She is a business technology journalist who previously reported for InformationWeek, where she covered Microsoft, and Insurance & Technology, where she covered financial ... View Full Bio

Comment  | 
Print  | 
More Insights
Comments
Newest First  |  Oldest First  |  Threaded View
Why Cyber-Risk Is a C-Suite Issue
Marc Wilczek, Digital Strategist & CIO Advisor,  11/12/2019
Unreasonable Security Best Practices vs. Good Risk Management
Jack Freund, Director, Risk Science at RiskLens,  11/13/2019
Register for Dark Reading Newsletters
White Papers
Video
Cartoon Contest
Current Issue
Navigating the Deluge of Security Data
In this Tech Digest, Dark Reading shares the experiences of some top security practitioners as they navigate volumes of security data. We examine some examples of how enterprises can cull this data to find the clues they need.
Flash Poll
Rethinking Enterprise Data Defense
Rethinking Enterprise Data Defense
Frustrated with recurring intrusions and breaches, cybersecurity professionals are questioning some of the industrys conventional wisdom. Heres a look at what theyre thinking about.
Twitter Feed
Dark Reading - Bug Report
Bug Report
Enterprise Vulnerabilities
From DHS/US-CERT's National Vulnerability Database
CVE-2019-14869
PUBLISHED: 2019-11-15
A flaw was found in all versions of ghostscript 9.x before 9.28, where the `.charkeys` procedure, where it did not properly secure its privileged calls, enabling scripts to bypass `-dSAFER` restrictions. An attacker could abuse this flaw by creating a specially crafted PostScript file that could esc...
CVE-2019-18987
PUBLISHED: 2019-11-15
An issue was discovered in the AbuseFilter extension through 1.34 for MediaWiki. Once a specific abuse filter has (accidentally or otherwise) been made public, its previous versions can be exposed, thus potentially disclosing private or sensitive information within the filter's definition.
CVE-2019-18986
PUBLISHED: 2019-11-15
Pimcore before 6.2.2 allow attackers to brute-force (guess) valid usernames by using the 'forgot password' functionality as it returns distinct messages for invalid password and non-existing users.
CVE-2019-18981
PUBLISHED: 2019-11-15
Pimcore before 6.2.2 lacks an Access Denied outcome for a certain scenario of an incorrect recipient ID of a notification.
CVE-2019-18982
PUBLISHED: 2019-11-15
bundles/AdminBundle/Controller/Admin/EmailController.php in Pimcore before 6.3.0 allows script execution in the Email Log preview window because of the lack of a Content-Security-Policy header.