Attacks/Breaches

11/7/2016
03:45 PM
Connect Directly
Twitter
LinkedIn
RSS
E-Mail
50%
50%

Was Theft Of Money From 20,000 Tesco Bank Customers An Inside Job?

UK bank confirms attack, but so far has not used the word 'hack.'

Threat actors appear to have broken new ground with an attack on the UK's Tesco Bank where they managed to steal money from more than 20,000 accounts at nearly the same time in automated fashion.

Details of the weekend attack are still just emerging, but Tesco has confirmed the breach and suspended the ability for current account customers to use their debit card for online transactions.

So far the company has not put any restrictions on the ability for affected customers to use their cards for cash withdrawals, direct debit, and bill payments. Current account customers are also still able to use their debit cards for chip-and-PIN payments.

In the statement announcing the incident, Tesco Bank CEO Benny Higgins reassured customers that any money stolen from their accounts would be reimbursed by end of day Tuesday.

The BBC Monday quoted Higgins as describing the theft as a systematic, sophisticated attack. The bank has already figured out exactly what happened but is unable to disclose details because of the ongoing investigation, Higgins told BBC. So far, the bank has not used the word “hack” in connection with the attack, BBC added.

In total, about 40,000 current accounts experienced suspicious transactions over the weekend and money was illegally withdrawn from about half of them.

Tesco has not revealed how much money the attackers managed to steal from its customers. But it has stressed that only relatively small amounts were stolen from consumer accounts the BBC said.

However, comments posted on Tesco bank’s community forum by irate customers suggest that at least some of them suffered substantial losses. One customer for example complained about a £2,400 loss while another spoke of a £600 dent in his or her account.

The Tesco attack is of course not the first attack on a major bank and it likely may not be the biggest in terms of losses, either. What makes it different is the sheer number of consumer accounts that were looted in what appears to be near-simultaneous fashion.

Typically, online bank heists have either involved individual account takeovers or attacks like those involving the SWIFT network earlier this year. Thousands of US individuals, small businesses, local governments, and school districts, for instance, have cumulatively lost hundreds of millions of dollars in recent years to account takeovers where attackers steal account credentials and use them to initiate illegal wire transfers.

The fact that attackers in the Tesco case somehow had simultaneous access to over 20,000 accounts suggests an inside job, says Greg Salyards, principal sales consultant at Identity Automation.

“I doubt a third-party gained access to and logged on with 20,000 plus client credentials to process transfers externally,” Salyards says. Instead, what likely happened is an IT administrator, bank processor, or contractor with the right credentials to either change client passwords or log on as the client, was somehow involved, Salyards says. But without more information, he notes, this is pure speculation.

“Some type of batch process was probably run internally by someone who has now boarded a flight to a country with no extradition agreement with the UK,” Salyards says.

Mark Wilson, director of product management at STEALTHbits Technologies, says it's highly unlikely the attacks were compromised in a single attack by an external attacker.

It is possible that an attacker managed to infiltrate malware past Tesco’s perimeter security and propagated it across the enterprise. Even so, unless there had been a serious breach of internal policies and processes, it is unlikely an external attacker would have acquired the privileges needed to access so customer accounts.

“If Tesco's data was secured as required by PCI and the various compliance bodies, then the likeliest candidate is a rogue administrator—or administrators,” Wilson says.

Related stories:

 

Jai Vijayan is a seasoned technology reporter with over 20 years of experience in IT trade journalism. He was most recently a Senior Editor at Computerworld, where he covered information security and data privacy issues for the publication. Over the course of his 20-year ... View Full Bio

Comment  | 
Print  | 
More Insights
Comments
Newest First  |  Oldest First  |  Threaded View
filthychats
50%
50%
filthychats,
User Rank: Apprentice
11/7/2016 | 8:14:41 PM
That's a lot of money
Even if only a third of the potentially affected accounts had money withdrawn with a mere $50 average, that is still well over half a million dollars lost. Ridiculous. 
6 Security Trends for 2018/2019
Curtis Franklin Jr., Senior Editor at Dark Reading,  10/15/2018
6 Reasons Why Employees Violate Security Policies
Ericka Chickowski, Contributing Writer, Dark Reading,  10/16/2018
Getting Up to Speed with "Always-On SSL"
Tim Callan, Senior Fellow, Comodo CA,  10/18/2018
Register for Dark Reading Newsletters
White Papers
Video
Cartoon
Latest Comment: Too funny!
Current Issue
Flash Poll
The Risk Management Struggle
The Risk Management Struggle
The majority of organizations are struggling to implement a risk-based approach to security even though risk reduction has become the primary metric for measuring the effectiveness of enterprise security strategies. Read the report and get more details today!
Twitter Feed
Dark Reading - Bug Report
Bug Report
Enterprise Vulnerabilities
From DHS/US-CERT's National Vulnerability Database
CVE-2018-10839
PUBLISHED: 2018-10-16
Qemu emulator <= 3.0.0 built with the NE2000 NIC emulation support is vulnerable to an integer overflow, which could lead to buffer overflow issue. It could occur when receiving packets over the network. A user inside guest could use this flaw to crash the Qemu process resulting in DoS.
CVE-2018-13399
PUBLISHED: 2018-10-16
The Microsoft Windows Installer for Atlassian Fisheye and Crucible before version 4.6.1 allows local attackers to escalate privileges because of weak permissions on the installation directory.
CVE-2018-18381
PUBLISHED: 2018-10-16
Z-BlogPHP 1.5.2.1935 (Zero) has a stored XSS Vulnerability in zb_system/function/c_system_admin.php via the Content-Type header during the uploading of image attachments.
CVE-2018-18382
PUBLISHED: 2018-10-16
Advanced HRM 1.6 allows Remote Code Execution via PHP code in a .php file to the user/update-user-avatar URI, which can be accessed through an "Update Profile" "Change Picture" (aka user/edit-profile) action.
CVE-2018-18374
PUBLISHED: 2018-10-16
XSS exists in the MetInfo 6.1.2 admin/index.php page via the anyid parameter.