Risk

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

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
Oldest First  |  Newest First  |  Threaded View
'PowerSnitch' Hacks Androids via Power Banks
Kelly Jackson Higgins, Executive Editor at Dark Reading,  12/8/2018
Higher Education: 15 Books to Help Cybersecurity Pros Be Better
Curtis Franklin Jr., Senior Editor at Dark Reading,  12/12/2018
Register for Dark Reading Newsletters
White Papers
Video
Cartoon Contest
Current Issue
10 Best Practices That Could Reshape Your IT Security Department
This Dark Reading Tech Digest, explores ten best practices that could reshape IT security departments.
Flash Poll
Twitter Feed
Dark Reading - Bug Report
Bug Report
Enterprise Vulnerabilities
From DHS/US-CERT's National Vulnerability Database
CVE-2018-20102
PUBLISHED: 2018-12-12
An out-of-bounds read in dns_validate_dns_response in dns.c was discovered in HAProxy through 1.8.14. Due to a missing check when validating DNS responses, remote attackers might be able read the 16 bytes corresponding to an AAAA record from the non-initialized part of the buffer, possibly accessing...
CVE-2018-20103
PUBLISHED: 2018-12-12
An issue was discovered in dns.c in HAProxy through 1.8.14. In the case of a compressed pointer, a crafted packet can trigger infinite recursion by making the pointer point to itself, or create a long chain of valid pointers resulting in stack exhaustion.
CVE-2018-1480
PUBLISHED: 2018-12-12
IBM BigFix Platform 9.2.0 through 9.2.14 and 9.5 through 9.5.9 does not set the 'HttpOnly' attribute on authorization tokens or session cookies. If a Cross-Site Scripting vulnerability also existed attackers may be able to get the cookie values via malicious JavaScript and then hijack the user sessi...
CVE-2018-1481
PUBLISHED: 2018-12-12
IBM BigFix Platform 9.2.0 through 9.2.14 and 9.5 through 9.5.9 stores sensitive information in URL parameters. This may lead to information disclosure if unauthorized parties have access to the URLs via server logs, referrer header or browser history. IBM X-Force ID: 140763.
CVE-2018-1484
PUBLISHED: 2018-12-12
IBM BigFix Platform 9.2.0 through 9.2.14 and 9.5 through 9.5.9 does not set the secure attribute on authorization tokens or session cookies. Attackers may be able to get the cookie values by sending a http:// link to a user or by planting this link in a site the user goes to. The cookie will be sent...