Netskope named a Leader in the 2022 Gartner® Magic Quadrant™ for Security Service Edge. Get the Report.

  • Products

    Netskope products are built on the Netskope Security Cloud.

  • Platform

    Unrivaled visibility and real-time data and threat protection on the world's largest security private cloud.

Netskope Named a Leader in the 2022 Gartner Magic Quadrant™ for SSE Report

Get the report Go to Products Overview
Netskope gartner mq 2022 sse leader

Netskope delivers a modern cloud security stack, with unified capabilities for data and threat protection, plus secure private access.

Explore our platform
Birds eye view metropolitan city

Make the move to market-leading cloud security services with minimal latency and high reliability.

Learn more
Lighted highway through mountainside switchbacks

Prevent threats that often evade other security solutions using a single-pass SSE framework.

Learn more
Lighting storm over metropolitan area

Zero trust solutions for SSE and SASE deployments

Learn more
Boat driving through open sea

Netskope enables a safe, cloud-smart, and fast journey to adopt cloud services, apps, and public cloud infrastructure.

Learn more
Wind turbines along cliffside
  • Our Customers

    Netskope serves more than 2,000 customers worldwide including more than 25 of the Fortune 100

  • Customer Solutions

    We are here for you and with you every step of the way, ensuring your success with Netskope.

  • Training and Certification

    Netskope training will help you become a cloud security expert.

We help our customers to be Ready for Anything

See our Customers
Woman smiling with glasses looking out window

Netskope’s talented and experienced Professional Services team provides a prescriptive approach to your successful implementation.

Learn more
Netskope Professional Services

Secure your digital transformation journey and make the most of your cloud, web, and private applications with Netskope training.

Learn more
Group of young professionals working
  • Resources

    Learn more about how Netskope can help you secure your journey to the cloud.

  • Blog

    Learn how Netskope enables security and networking transformation through security service edge (SSE).

  • Events & Workshops

    Stay ahead of the latest security trends and connect with your peers.

  • Security Defined

    Everything you need to know in our cybersecurity encyclopedia.

Security Visionaries Podcast

Episode 15: Building Permanent Security Awareness

Play the podcast
Black man sitting in conference meeting

Read the latest on how Netskope can enable the Zero Trust and SASE journey through security service edge (SSE) capabilities.

Read the blog
Sunrise and cloudy sky

SASE Week

Netskope is positioned to help you begin your journey and discover where Security, Networking, and Zero Trust fit in the SASE world.

Learn more
SASE Week

What is Security Service Edge?

Explore the security side of SASE, the future of network and protection in the cloud.

Learn more
Four-way roundabout
  • Company

    We help you stay ahead of cloud, data, and network security challenges.

  • Why Netskope

    Cloud transformation and work from anywhere have changed how security needs to work.

  • Leadership

    Our leadership team is fiercely committed to doing everything it takes to make our customers successful.

  • Partners

    We partner with security leaders to help you secure your journey to the cloud.

Netskope enables the future of work.

Find out more
Curvy road through wooded area

Netskope is redefining cloud, data, and network security to help organizations apply Zero Trust principles to protect data.

Learn more
Switchback road atop a cliffside

Thinkers, builders, dreamers, innovators. Together, we deliver cutting-edge cloud security solutions to help our customers protect their data and people.

Meet our team
Group of hikers scaling a snowy mountain

Netskope’s partner-centric go-to-market strategy enables our partners to maximize their growth and profitability while transforming enterprise security.

Learn more
Group of diverse young professionals smiling

A Malicious Sight in Google Sites

Apr 23 2019
Tags
google
Google sites
LoadPCBanker

Netskope Threat Research Labs discovered an interesting drive-by download attack in Google. The threat actor involved in this attack initially deployed a Banking Trojan using the file cabinets template in Google sites as a delivery vehicle. The malware dubbed “LoadPCBanker” used SQL as an exfiltration channel to send the compromised victim data to the server.

There are two aspects of this attack that are noteworthy:

  1. First, users place an implicit trust to vendors like Google. As a result, they are more likely to fall victim to an attack launched from within a Google service.
  2. Second, whereas other services like Gmail block some malicious file uploads, Google File Cabinet does not appear to have any such protections.

This post describes our discovery and analysis of the attack and the malware payload. We will also conclude with some recommendations to help protect and remediate such threats.

Netskope Detection

Netskope Advanced Threat Protection detects the malware associated with this attack as Win32.LoadPCBanker.Gen.

Netskope customers can also create a policy to generically block all uploads and downloads from Google sites as shown in Figure 1.

Figure 1: Block policy for upload and download activity in Google Sites

Disclosure

Netskope reported the associated Google sites hosting malware using the report abuse option to Google on 12 April 2019.

Malware hosted Google Sites

We originally found the malware being delivered from the following Google Sites URL:https://sites.google[.]com/site/detailsreservations/Reserva-Manoel_pdf.rar?attredirects=0&d=1.

The files are being hosted using the classic Google Sites. Using the ‘Recent site activity’ option on the site containing the file, we found out there were two files resident at the top level, as shown in Figure 2.

Figure 2: Reserva-Manoel_pdf.rar at the top level in the Google Sites

The threat actor used classic Google sites to create a website, then used the file cabinet template to upload the payload, and finally sent the resulting URL to the potential targets. A visual depiction of this process is shown in Figure 3.

Figure 3: Depiction of the delivery mechanism of the malware using Google sites

Attack Kill chain

The depiction of the attack kill chain of the LoadPCBanker malware is shown in Figure 4. It begins with a first-stage parent downloader, which downloads the next stage payloads from a file hosting website. The next stage payloads collect screenshots, clipboard data, and keystrokes from the victim.  Finally, it uses SQL, an exfiltration channel to send the victim data to the server.

Figure 4: Attack Kill chain of LoadPCBanker

Analysis of LoadPCBanker

The downloaded RAR archive “Reserva-Manoel_pdf.rar” contained an executable ”PDF Reservations Details MANOEL CARVALHO hospedagem familiar detalhes PDF.exe”. The filename translates to “PDF Reservations Details MANOEL CARVALHO guest house details PDF.exe” from Portuguese to English, indicating to be likely targeting Brazil or Portuguese speaking users.

The malicious executable compiled in Delphi uses a PDF document icon disguise as shown in Figure 5.

Figure 5: PDF icon used in the executable

This sample primarily works as a downloader to download the next stage payloads. On execution, a hidden folder named ‘clientpc’ is created in the C drive. Then, the next-stage payloads libmySQL50.DLL, otlook.exe, and cliente.dll are downloaded to this same location from a file hosting website, kinghost[.]net, using the URL drivemailcompartilhamentoanexos[.]kinghost.net, as shown in Figure 6.

Figure 6: Next stage payloads downloaded from drivemailcompartilhamentoanexos[.]kinghost.net

While Otlook.exe and cliente.dll are malicious files, libmySQL50.DL is a library of mysql. The threat actor used libmySQL50.DLL as a to send the victim data to the server. Next, otlook.exe is executed. The downloader deletes all its download URLs from the system’s WinINet cache as shown in Figure 7.

Figure 7: Delete URL cache

Once this is done, the malware further connects to the URL hosted in zzz.com[.]ua to notify the victim has been infected with the malware, as shown in Figure 8.

Figure 8: Connection to  zzz.com[.]ua

Analysis of the Next Stage Payloads

Otlook.exe is a delphi compiled executable that loads libmySQL50.DLL and cliente.dll during execution, as shown in Figure 9.

Figure 9: Otlook.exe loading libmySQL50.DLL and cliente.dll during execution

Its functions primarily as spyware, doing the following:

  • Records screenshots and saves as saves the file name as screen<number>.jpg in the location “C:\clientpc” (using API’s GetDesktopWindow, GetDC)
  • Records the clipboard data in the location “C:\clientpc\capctrl.txt” (using the API GetClipboardData)
  • Records all the keystrokes in the location “C:\clientpc\relatorio.log” (using the API GetAsyncKeyState)
  • Similar to the first stage downloader, delets all its download URLs from the WinINet cache.

Otlook.exe downloads a file named “dblog.log” from the URL http://www.albumdepremios.com[.]br/hostmeu with the User-Agent: Otlook as shown in Figure 10.

Figure 10: dblog.log downloaded from http://www.albumdepremios.com[.]br/hostmeu

It contains the external SQL database server credentials in an encoded format. This is decoded in the decryption loop present in otlook.exe as shown in Figure 11.

Figure 11: Decryption loop for dblog.log

The decoded values contain the credentials of the server,user_name, password, port, and database to exfiltrate the victim details to the SQL server as shown in Figure 12.

Figure 12:  SQL database credentials

An export of the SQL C2 exfiltration is shown in Figure 13.

Figure 13: SQL exfiltration

Otlook.exe also downloaded two cfg files named cliente.cfg and filtro.cfg from the URL http://www.albumdepremios[.]com.br/heisen to the location “C:\clientpc”. The cfg files contained the configuration details like DNS, port, log, ID and filter for the connection. We also observed that the attacker constantly rotated the database credentials by updating the dblog.log file.

The SQL database contained a database and two tables in the server as shown in Figure 14.

Figure 14: SQL server database and tables

During our analysis, we identified that the threat actor was particularly interested in surveilling a specific set of machines and capturing screenshots of the victims’ machines that were compromised from this attack. We derived this because we noticed a lot of infected machine responses, but only a few were being actively surveilled. At the time of writing, the threat actor was actively monitoring 20 infected hosts.

Similar strains – Ties and connections

Using VirusTotal Passive DNS, we were able to identify similar samples communicating to the C2 – albumdepremios[.]com.br, as shown in Figure 15.

Figure 15: Passive DNS records of albumdepremios[.]com.br

We believe that similar malware has been around since early 2014, and this latest wave of attacks has been ongoing since February 2019, based on the passive DNS results and our in-house threat intelligence framework. It is possible that the same threat actor has been involved in these attacks, or the source code has been reused by multiple actors over this period.

As we continued our analysis on the similar strains, ties, and connections, we identified another Google sites URL created by the threat actor. The site activity is shown in Figure 16.

Figure 16: Similar malware hosted in Google sites

The modus operandi is the same but the first stage downloader URL’s have been updated as shown in Figure 17.

Figure 17: First stage downloader Urls updated

The Whois Record of the C2, albumpremios[.]com.br, is shown in Figure 18.

Figure 18: Whois Record of albumpremios[.]com.br

The Whois Record states the website was created in 2014 March and hosted in Brazil. Based on the details collected there is a high degree of confidence that the threat actor is targeting individuals from Brazil.

Conclusion

We identified Banking malware named “LoadPcBanker” delivered via Google sites, targeting individuals from Brazil, and using SQL as an exfiltration channel.

We also discovered the threat actor used the file cabinets template from classic Google sites to host malware, and that the uploads are not blocked by Google. Though the usage of Google Sites appears new, using our in-house systems, sample repositories, and Netskope Threat Intelligence Framework, we were able to trace the origins of this attack back to early 2014.

Netskope Threat Research Labs will continue to monitor the delivery mechanism and developments of the threat actor.

Credits: Thanks to Arun Prabhu Dhandapani for the assistance and inputs on the SQL server of the attacker.

Recommendations

Netskope recommends the following to combat malware campaigns:

  • Always check the domain of the link. Know the domains typically used when you log in to sensitive services. Additionally, be able to identify common object store domains. This knowledge will help you differentiate between well-crafted phishing/malware sites and official sites.
  • Deploy a real-time visibility and control solution to monitor activities across sanctioned and unsanctioned cloud accounts.
  • Get comprehensive threat and malware detection for IaaS, SaaS, PaaS, and the web with real-time, multi-layered threat detection and remediation to prevent your organization from unknowingly spreading similar threats.
  • Actively track usage of unsanctioned cloud apps and enforce DLP policies to control files and data entering and leaving your corporate environment
  • Create a security policy to block PE files with a different file-content type ”image/png” “image/jpg”
  • Warn users against opening untrusted attachments, regardless of their extensions or filenames.
  • Warn users to avoid executing any file unless they are very sure that they are benign, even if the file is delivered from appears to be something legitimate, like sites.google.com
  • Hover your mouse over all hyperlinks to confirm them before clicking on the link.
  • Enable Two-factor authentication for email accounts as a safety measure to prevent attackers from accessing the email account even if they know the password
  • Keep systems and antivirus updated with the latest releases and patches
author image
Ashwin Vamshi
Ashwin Vamshi is a Security Researcher with innate interest in targeted attacks and malwares using cloud services. He is primarily focusing in identifying new attack vectors and malwares, campaigns and threat actors using ‘cloud as an attack vector.’