Stolen Pencil Trojan

Stolen Pencil, also known as Stolepen, is a trojan that targets devices using Google Chrome on Microsoft Windows. It was first observed in May 2018.

Threat ID:: CC-2852
Category:: Trojan
Threat Severity:: Medium
Threat Vector:: Spear phishing
Published:: 20 December 2018 12:00 AM

Report a cyber attack: call 0300 303 5222 or email [email protected]

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Summary

Stolen Pencil, also known as Stolepen, is a trojan that targets devices using Google Chrome on Microsoft Windows. It was first observed in May 2018.

Affected platforms

The following platforms are known to be affected:

Microsoft Windows

Google Chrome for Microsoft Windows - All versions

Threat details

Stolen Pencil is distributed through a spear phishing campaign that contains a malicious PDF attachment. Once opened, the PDF will prompt the user to install a malicious Chrome extension.

Once installed, Stolen Pencil will log keystrokes and replace Ethereum wallet addresses with the attacker’s own wallet. The malware will also create administrator accounts, enable Remote Desktop Protocol (RDP) on the compromised device, and then add RDP as an exception to firewall rules.

Remediation steps

Type	Step
	To prevent and detect a trojan infection, ensure that: A robust program of education and awareness training is delivered to users to ensure they don’t open attachments or follow links within unsolicited emails. All operating systems, anti-virus and other security products are kept up-to-date. Regular anti-virus and security scans are performed on your organisation’s estate. All day-to-day computer activities such as email and internet are performed using non-administrative accounts. Strong password policies are in place. Network, proxy and firewall logs should be monitored for suspicious activity. User accounts accessed from affected devices should be reset on a clean computer. Your organisation adopts a holistic all-round approach to Cyber Security as advocated by the 10 Steps to Cyber Security. If Remote Desktop Protocol (RDP) is not used, then ensure port 3389 (TCP/UDP) is blocked at your internet firewall. If RDP is used, then: Ensure network level authentication is enabled. Only allow access for authorised RDP users. Enforce strong password policies. Enforce multi-factor authentication. Don't allow RDP access for privileged user accounts. Don’t use generic accounts. Set user accounts with an expiry date. Audit user accounts periodically. Only allow point-to-point connections from specific IP addresses where feasible. Ensure Transport Layer Security (TLS) is up-to-date. Log and monitor all RDP activity and investigate unusual behaviour. Consider only allowing RDP for authorised virtual private network (VPN) connections.

Type

Step

To prevent and detect a trojan infection, ensure that:

A robust program of education and awareness training is delivered to users to ensure they don’t open attachments or follow links within unsolicited emails.
All operating systems, anti-virus and other security products are kept up-to-date.
Regular anti-virus and security scans are performed on your organisation’s estate.
All day-to-day computer activities such as email and internet are performed using non-administrative accounts.
Strong password policies are in place.
Network, proxy and firewall logs should be monitored for suspicious activity.
User accounts accessed from affected devices should be reset on a clean computer.
Your organisation adopts a holistic all-round approach to Cyber Security as advocated by the 10 Steps to Cyber Security.

If Remote Desktop Protocol (RDP) is not used, then ensure port 3389 (TCP/UDP) is blocked at your internet firewall. If RDP is used, then:

Ensure network level authentication is enabled.
Only allow access for authorised RDP users.
Enforce strong password policies.
Enforce multi-factor authentication.
Don't allow RDP access for privileged user accounts.
Don’t use generic accounts.
Set user accounts with an expiry date.
Audit user accounts periodically.
Only allow point-to-point connections from specific IP addresses where feasible.
Ensure Transport Layer Security (TLS) is up-to-date.
Log and monitor all RDP activity and investigate unusual behaviour.
Consider only allowing RDP for authorised virtual private network (VPN) connections.

Last edited: 11 January 2022 9:38 am