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Discovered: April 17, 2019
Updated: April 18, 2019 7:16:16 AM
Type: Trojan
Infection Length: Varies
Systems Affected: Windows

Infostealer.Scranos is a Trojan horse that steals information from the compromised computer. It may also download potentially malicious files.

Antivirus Protection Dates

  • Initial Rapid Release version April 17, 2019 revision 023
  • Latest Rapid Release version June 08, 2019 revision 016
  • Initial Daily Certified version April 18, 2019 revision 001
  • Latest Daily Certified version June 09, 2019 revision 002
  • Initial Weekly Certified release date April 24, 2019

Click here for a more detailed description of Rapid Release and Daily Certified virus definitions.

Technical Description

The threat spreads via Trojanized applications disguised as cracked software, or applications posing as legitimate software such as e-book readers, video players, drivers, or even antivirus products.

When the Trojan is executed, it creates the following folders:

  • HKEY_CURRENT_USER\Software\demo

The Trojan may perform the following malicious actions on the compromised computer:
  • Extract cookies and steal login credentials from Google Chrome, Chromium, Mozilla Firefox, Opera, Microsoft Edge, Internet Explorer, Baidu browser, and Yandex browser
  • Steal users' payment accounts from their Facebook, Amazon, and Airbnb webpages
  • Send friend requests to other accounts from the user's Facebook account
  • Send phishing messages to the victim's Facebook friends containing malicious APKs used to infect Android users as well
  • Steal login credentials for the user's Steam account on Steam
  • Inject JavaScript adware into Internet Explorer
  • Install Chrome/Opera extensions to inject JavaScript adware on these browsers as well
  • Exfiltrate browsing history
  • Silently display ads or muted YouTube videos to users via Chrome (some variants can install Chrome if it is not already on the compromised computer)
  • Subscribe users to YouTube video channels
  • Download and execute any payload

The Trojan is packed with a kernel-level rootkit which is dropped and executed by the dropper. The rootkit ensures persistence and other critical functions, such as code injection and execution of a downloader component into svchost.exe .

The injected downloader then sends the gathered information to its command and control (C&C) server and receives further instructions with links to download payloads suited for that particular user.


Symantec Security Response encourages all users and administrators to adhere to the following basic security "best practices":

  • Use a firewall to block all incoming connections from the Internet to services that should not be publicly available. By default, you should deny all incoming connections and only allow services you explicitly want to offer to the outside world.
  • Enforce a password policy. Complex passwords make it difficult to crack password files on compromised computers. This helps to prevent or limit damage when a computer is compromised.
  • Ensure that programs and users of the computer use the lowest level of privileges necessary to complete a task. When prompted for a root or UAC password, ensure that the program asking for administration-level access is a legitimate application.
  • Disable AutoPlay to prevent the automatic launching of executable files on network and removable drives, and disconnect the drives when not required. If write access is not required, enable read-only mode if the option is available.
  • Turn off file sharing if not needed. If file sharing is required, use ACLs and password protection to limit access. Disable anonymous access to shared folders. Grant access only to user accounts with strong passwords to folders that must be shared.
  • Turn off and remove unnecessary services. By default, many operating systems install auxiliary services that are not critical. These services are avenues of attack. If they are removed, threats have less avenues of attack.
  • If a threat exploits one or more network services, disable, or block access to, those services until a patch is applied.
  • Always keep your patch levels up-to-date, especially on computers that host public services and are accessible through the firewall, such as HTTP, FTP, mail, and DNS services.
  • Configure your email server to block or remove email that contains file attachments that are commonly used to spread threats, such as .vbs, .bat, .exe, .pif and .scr files.
  • Isolate compromised computers quickly to prevent threats from spreading further. Perform a forensic analysis and restore the computers using trusted media.
  • Train employees not to open attachments unless they are expecting them. Also, do not execute software that is downloaded from the Internet unless it has been scanned for viruses. Simply visiting a compromised Web site can cause infection if certain browser vulnerabilities are not patched.
  • If Bluetooth is not required for mobile devices, it should be turned off. If you require its use, ensure that the device's visibility is set to "Hidden" so that it cannot be scanned by other Bluetooth devices. If device pairing must be used, ensure that all devices are set to "Unauthorized", requiring authorization for each connection request. Do not accept applications that are unsigned or sent from unknown sources.
  • For further information on the terms used in this document, please refer to the Security Response glossary.


You may have arrived at this page either because you have been alerted by your Symantec product about this risk, or you are concerned that your computer has been affected by this risk.

Before proceeding further we recommend that you run a full system scan. If that does not resolve the problem you can try one of the options available below.

If you are a Norton product user, we recommend you try the following resources to remove this risk.

Removal Tool
Use our tools to remove aggressive risks from your computer.

Infected Windows system files may need to be repaired using the Windows installation CD .

How to reduce the risk of infection
Check out our extensive collection of helpful advice and tips on how to stay safe online .

If you are a Symantec business product user, we recommend you try the following resources to remove this risk.

Identifying and submitting suspect files
Submitting suspicious files to Symantec allows us to ensure that our protection capabilities keep up with the ever-changing threat landscape. Submitted files are analyzed by Symantec Security Response and, where necessary, updated definitions are immediately distributed through LiveUpdate™ to all Symantec end points. This ensures that other computers nearby are protected from attack. The following resources may help in identifying suspicious files for submission to Symantec.

Removal Tool

If you have an infected Windows system file, you may need to replace it using the Windows installation CD .

The following instructions pertain to all current Symantec antivirus products.

1. Performing a full system scan
For information on how to run a full system scan using your Symantec product, follow the guidance given in the product's Help section.

2. Restoring settings in the registry
Many risks make modifications to the registry, which could impact the functionality or performance of the compromised computer. While many of these modifications can be restored through various Windows components, it may be necessary to edit the registry. See in the Technical Details of this writeup for information about which registry keys were created or modified. Delete registry subkeys and entries created by the risk and return all modified registry entries to their previous values.

Writeup By: Muhammad Hasib Latif