Paypal issue allows disclosure of account balance and recent transactions
24.2.2018 securityaffairs Safety

Paypal issue allows for enumeration of the last four digits of payment method and for the disclosure of account balance and recent transactions of any given PayPal account.
This post details an issue which allows for enumeration of the last four digits of payment method (such as a credit or debit card) and for the disclosure of account balance and recent transactions of any given PayPal account.

This attack was submitted to PayPal’s bug bounty program where it was classified as being out of scope, which is something that would admittedly be unavailing to refute since their program scope does not mention anything about attacks on their interactive voice response system.

PayPal ticket

Prerequisites and Reconnaissance
In order to get started, the attacker would require knowledge of two pieces of information pertaining to an account, which would be the e-mail address and phone number linked to it.

Armed with knowledge of the e-mail address and phone number linked to an account, the attacker would visit the Forgot Password page on PayPal’s website, and enter the e-mail address associated with the targeted account.

The attacker would then be presented with the type of card linked to the account, as well as the last two digits of the same.

PayPal - Forgot Password

Attacking the Interactive Voice Response System
On first glance, the interactive voice response system on PayPal’s phone-based customer support seemingly allows for a maximum of three attempts at submitting the correct last four digits per phone call.

However, if the first attempt at submission is incorrect, the caller will not be notified of a successful submission in subsequent attempts made during the same phone call. This makes any additional attempts given to a caller during the same phone call completely cosmetic.

To get around this presumed limitation, the attacker would have to make only one attempt at submitting a possible combination of the last four digits per phone call.

PayPal - Customer Support

Additionally, limiting the number of attempts to one submission per phone call makes the task of enumerating the correct combination much more time-efficient, and not to mention, it allows for easily distinguishing between a correct attempt and an incorrect one.

Furthermore, upon have tested this theory with my own account, I have been able to conclude that there is no limit on the number of submission attempts which can be made in this manner, meaning that hypothetically, an attacker could call 100,000 times to enumerate the last four digits entirely on their own.

That would, however, be disregarding the last two digits retrieved from the Forgot Password page, the knowledge of which effectively makes the attack much more feasible–by reducing the number of possible combinations from 100,000 to just 100.

Once the correct combination of the last four digits has been found, the attacker would simply have to use the interactive voice response system to retrieve information about the account.

After having entered the correct last four digits, the account’s current balance will automatically read off by the machine.

Additionally, to retrieve information about recent transactions, an attacker would simply have to say “recent transactions”, and the same would then be read off.

Attack Efficacy and Efficiency
If the aforementioned prerequisites have been met, an attacker would without fail have the ability to enumerate the correct last four digits of the payment method linked to an account. This information could then further be used to retrieve the account’s current balance and recent transactions as well.

Moreover, after having timed various attempts at submission of the last four digits, it was found that an attempt at submission would on average take around 30 seconds. The fastest possible time would be 27 seconds per phone call.

If we take the fastest possible time as our average, enumerating all possible combinations from 00XX to 99XX would take at most around 45 minutes. This time could then be halved by adding another phone in the mix to consecutively make calls with.

Possible Fixes
Users should be allowed to opt for privacy settings which keep the amount of data revealed on the Forgot Password page to a minimum. This would be similar to how Twitter allows its users to hide information about the email address and/or phone number linked to their account when attempting to reset its password.

It would also be similar to how Facebook allows users to choose whether their full names show up or not when their e-mail address is entered on the password reset page.

Perhaps some measures could be deployed where the last two digits of credit or debit card, if they need to be shown at all, are only shown when the request matches a certain criteria, such as if/when the request has been made from a recognizable device or location.

This issue allows for enumeration of the last four digits of the payment method on an account, which then allows for the disclosure of the account’s current balance and recent transactions.

An attacker with knowledge of the targeted account’s email address and phone number would first use PayPal’s Forgot Password page to retrieve the last two digits of the payment method linked to the account.

The attacker would then be able to accurately enumerate the last four–or rather the first two of the last four digits–of the payment method on the account by making phone calls to PayPal’s phone-based customer support and interacting with the interactive voice response system.

Once the attacker has successfully enumerated the last four digits of credit/debit card or bank account linked to the account, they would then be able to query the current account balance and recent transaction information at will.

Lastly, I would like to note that since there is no human interaction required or involved in the attack, it would essentially be a backdoor into PayPal accounts–allowing attackers to query current account balance and recent transaction information of any given account, at any time.

Czech President Wants Hacker 'Extradited to Russia' Not US
24.2.2018 securityweek BigBrothers

The Czech Republic's pro-Moscow president has repeatedly lobbied for a Russian hacker held in Prague and wanted by the US to be extradited to Russia, the justice minister was quoted as saying Saturday.

Yevgeni Nikulin, sought by the US for alleged cyberattacks on social networks and also by his native Russia on fraud charges, has been in a Prague prison since he was arrested in the Czech capital in October 2016 in a joint operation with the FBI.

The case comes amid accusations by Washington that Russia tried to "interfere" through hacking in the 2016 US election won by Donald Trump, charges the Kremlin has dismissed.

Last May, a Prague court ruled that the 30-year-old Nikulin can be extradited to either Russia or the United States, with the final say left to Justice Minister Robert Pelikan.

"It's true that there have been two meetings this year at which the president (Milos Zeman) asked me to extradite a Russian citizen not to the United States, but to Russia," Pelikan told the news site.

The site said the meetings had taken place in January, while earlier this week Pelikan received Vratislav Mynar, the head of Zeman's office, who also lobbied for Nikulin's extradition to Russia.

"It's none of your business, but I have handed the minister a letter from the detained Nikulin's mother," Mynar told

Zeman's spokesman Jiri Ovcacek declined to comment on the matter when asked by AFP.

Following Nikulin's arrest, Moscow accused Washington of harassing its citizens and vowed to fight Nikulin's extradition.

It then issued a separate arrest warrant for him over alleged theft from the WebMoney settlement system.

The US has charged Nikulin with hacking into social networks LinkedIn and Formspring and into the file hosting service Dropbox, Nikulin's lawyer Martin Sadilek told AFP earlier.

He also said Nikulin alleges that FBI investigators had tried twice to persuade him to confess to cyberattacks on the US Democratic Party.

Zeman, a 73-year-old ex-communist with strong pro-Russian, pro-Chinese and anti-Muslim views, won a second five-year term in a presidential vote in January.

2,000 Computers at Colorado DOT were infected with the SamSam Ransomware
24.2.2018 securityaffairs

SamSam Ransomware hit the Colorado DOT, The Department of Transportation Agency Shuts Down 2,000 Computers after the infection.
SamSam ransomware made the headlines again, this time it infected over 2,000 computers at the Colorado Department of Transportation (DOT).

The DOT has shut down the infected workstations and is currently working with security firm McAfee to restore the ordinary operations. Officials confirmed the ransomware requested a bitcoin payment.

“The Colorado Department of Transportation has ordered an estimated 2,000 employees to shut down their computers following a ransomware attack Wednesday morning.” wrote the CBS Denver.

The CDOT spokesperson Amy Ford said employees were instructed to turn off their computers at the start of business Wednesday after ransomware infiltrated the CDOT network.

“We’re working on it right now,” added Ford.

The good news is that crucial systems at the Colorado DOT such as surveillance cameras, traffic alerts were not affected by the ransomware.

David McCurdy, OIT’s Chief Technology Officer, issued the following statement:

“Early this morning state security tools detected that a ransomware virus had infected systems at the Colorado Department of Transportation. The state moved quickly to quarantine the systems to prevent further spread of the virus. OIT, FBI and other security agencies are working together to determine a root cause analysis. This ransomware virus was a variant and the state worked with its antivirus software provider to implement a fix today. The state has robust backup and security tools and has no intention of paying ransomware. Teams will continue to monitor the situation closely and will be working into the night.”

The Colorado DOT officials confirmed that the agency will not pay the ransom and it will restore data from backups.

The SamSam ransomware is an old threat, attacks were observed in 2015 and the list of victims is long, many of them belong to the healthcare industry. The attackers spread the malware by gaining access to a company’s internal networks by brute-forcing RDP connections.

Among the victims of the Samsam Ransomware there is the MedStar non-profit group that manages 10 hospitals in the Baltimore and Washington area. Crooks behind the attack on MedStar requested 45 Bitcoins (about US$18,500) for restoring the encrypted files, but the organization refused to pay the Ransom because it had a backup of the encrypted information.

In April 2016, the FBI issued a confidential urgent “Flash” message to the businesses and organizations about the Samsam Ransomware.

Back to the present, the Samsam Ransomware made the headlines in the first days of 2018, the malicious code infected systems of some high-profile targets, including hospitals, an ICS firm, and a city council.

SamSam ransomware

Iran-linked group OilRig used a new Trojan called OopsIE in recent attacks
24.2.2018 securityaffairs BigBrothers  APT

According to malware researchers at Palo alto Networks, the Iran-linked OilRig APT group is now using a new Trojan called OopsIE.
The Iran-linked OilRig APT group is now using a new Trojan called OopsIE, experts at Palo Alto Networks observed the new malware being used in recent attacks against an insurance agency and a financial institution in the Middle East.

One of the attacks relied on a variant of the ThreeDollars delivery document, the same malicious document was sent by the threat actor to the UAE government to deliver the ISMInjector Trojan.

In the second attack detected by PaloAlto, the OilRig hackers attempted to deliver the malicious code via a link in a spear phishing message.

“On January 8, 2018, Unit 42 observed the OilRig threat group carry out an attack on an insurance agency based in the Middle East. Just over a week later, on January 16, 2018, we observed an attack on a Middle Eastern financial institution. In both attacks, the OilRig group attempted to deliver a new Trojan that we are tracking as OopsIE.” reads the analysis from Palo Alto Networks.

The first attack occurred on January 8, 2018, the hackers sent two emails to two different email addresses at the target organization within a six minutes time span. Attackers spoofed the email address associated with the Lebanese domain of a major global financial institution.

OilRig launched another attack on January 16, in this case, the attackers downloaded the OopsIE Trojan from the command and control (C&C) server directly. The same organization was hit by OilRig for the second time, the first attacks occurred in 2017.

The researchers explained that the malware is packed with SmartAssembly and obfuscated with ConfuserEx.

The hackers gain persistence by creating a VBScript file and a scheduled task to run itself every three minutes. The OopsIE Trojan communicates with the C&C over HTTP by using the InternetExplorer application object.

“By using the InternetExplorer application object, all C2 related requests will look as if they came from the legitimate browser and therefore will not contain any anomalous fields within the request, such as custom User-Agents. The OopsIE Trojan is configured to use a C2 server hosted at:

www.msoffice365cdn[.]com” states the analysis.

“The Trojan will construct specific URLs to communicate with the C2 server and parses the C2 server’s response looking for content within the tags <pre> and </pre>. The initial HTTP request acts as a beacon”


The Trojan can run a command, upload a file, or download a specified file.

Oilrig will continue to adapt its tactics, the experts believe that it will remain a highly active threat actor in the Middle East region.

“This group has repeatedly shown evidence of a willingness to adapt and evolve their tactics, while also reusing certain aspects as well. We have now observed this adversary deploy a multitude of tools, with each appearing to be some form of iterative variation of something used in the past. However, although the tools themselves have morphed over time, the plays they have executed in their playbook largely remain the same when examined over the attack life cycle,” Palo Alto concludes.

FBI warns of spike in phishing campaigns to gather W-2 information
24.2.2018 securityaffairs BigBrothers

The FBI is warning of a spike in phishing campaigns aimed to steal W-2 information from payroll personnel during the IRS’s tax filing season.
The FBI has observed a significant increase since January of complaints of compromised or spoofed emails involving W-2 information.

“Beginning in January 2017, IRS’s Online Fraud Detection & Prevention (OFDP), which monitors for suspected IRS-related phishing emails, observed an increase in reports of compromised or spoofed emails requesting W-2 information.” states the alert published by the FBI.

W-2 information is a precious commodity for crooks that are showing an increasing interest in tax data.

Law enforcement and security experts observed many variations of IRS and tax-related phishing campaigns, but most effective are mass data thefts, for example, campaigns targeting Human Resource (HR) professionals.

“The most popular method remains impersonating an executive, either through a compromised or spoofed email in order to obtain W-2 information from a Human Resource (HR) professional within the same organization.” continues the alert.

“Individual taxpayers may also be the targeted, but criminals have evolved their tactics to focus on mass data thefts.”

w-2 information

A separate warning od W-2 -related phishing campaigns was issued by the Internal Revenue Service.

“The Form W-2 scam has emerged as one of the most dangerous phishing emails in the tax community. During the last two tax seasons, cybercriminals tricked payroll personnel or people with access to payroll information into disclosing sensitive information for entire workforces.” reads the IRS’s advisory issued in January. “The scam affected all types of employers, from small and large businesses to public schools and universities, hospitals, tribal governments and charities.”

Once cyber criminal obtained the W-2 information, they will request a wire transfer, unfortunately, in the case of businesses and organizations the scam is not discovered for weeks or months.

“The initial email may be a friendly, “hi, are you working today” exchange before the fraudster asks for all Form W-2 information. In several reported cases, after the fraudsters acquired the workforce information, they immediately followed that up with a request for a wire transfer.” continues the advisory.

“In addition to educating payroll or finance personnel, the IRS and Security Summit partners also urge employers to consider creating a policy to limit the number of employees who have authority to handle Form W-2 requests and that they require additional verification procedures to validate the actual request before emailing sensitive data such as employee Form W-2s.”

Phishing scams related W-2 information have been increasing, the number of reports regarding this criminal practice from both victims and non-victims jumped from over 100 in 2016 up to roughly 900 in 2017, The IRS confirmed that more than 200 employers were victimized in 2017.

“Reports to from victims and nonvictims about this scam jumped to approximately 900 in 2017, compared to slightly over 100 in 2016. Last year, more than 200 employers were victimized, which translated into hundreds of thousands of employees who had their identities compromised.” continues the alert.

Let me close with recommendations published by the FBI to avoid being victims of W-2 phishing scams and BEC:

Limit the number of employees within a business who have the authority to approve and/or conduct wire transfers and handle W-2 related requests or tasks
Use out of band authentication to verify requests for W-2 related information or wire transfer requests that are seemingly coming from executives. This may include calling the executive to obtain verbal verification, establishing a phone Personal Identification Number (PIN) to verify the executive’s identity, or sending the executive via text message a one-time code and a phone number to call in order to confirm the wire transfer request
Verify a change in payment instructions to a vendor or supplier by calling to verbally confirm the request. The phone number should not come from the electronic communication, but should instead be taken from a known contact list for that vendor
Maintain a file, preferably in non-electronic form, of vendor contact information for those who are authorized to approve changes in payment instructions
Delay the transaction until additional verifications can be performed such as having staff wait to be contacted by the bank to verify the wire transfer
Require dual-approval for any wire transfer request involving one or more of the following:
A dollar amount over a specific threshold
Trading partners who have not been previously added to a “white list” of approved trading partners to receive wire payments
New trading partners
New bank and/or account numbers for current trading partners
Wire transfers to countries outside of the normal trading pattern