Trojan:SymbOS/MerogoSMS

Classification

Malware

Trojan

SymbOS

-

Summary

Also known as a trojan horse program, this is a deceptive program that performs additional actions without the user's knowledge or permission.

Automatic action

If found, remove the following from the application manager:

  • Symbian S60 AknMime Services
  • Symbian S60 System InsSrv
  • Symbian S60 System UpdateSrv

Suspect a file is incorrectly detected (a False Positive)?

A False Positive is when a file is incorrectly detected as harmful, usually because its code or behavior resembles known harmful programs. A False Positive will usually be fixed in a subsequent database update without any action needed on your part. If you wish, you may also:

  • Check for the latest database updates

    First check if your F-Secure security program is using the latest detection database updates, then try scanning the file again.

  • Submit a sample

    After checking, if you still believe the file is incorrectly detected, you can submit a sample of it for re-analysis.

    NOTE If the file was moved to quarantine, you need to collect the file from quarantine before you can submit it.

  • Exclude a file from further scanning

    If you are certain that the file is safe and want to continue using it, you can exclude it from further scanning by the F-Secure security product.

    Note You need administrative rights to change the settings.

For more Support

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User Guide

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Submit a sample

Submit a file or URL for further analysis.

Technical Details

Trojan:SymbOS/MerogoSMS refers to a series of SMS worms that has been found spreading on Symbian Series 60 3rd Edition and Symbian Series 60 5th Edition devices. The worm spreads as self-signed (untrusted) SIS installers, which contain sub-SIS installers some of them signed by Symbian. All the related publisher IDs and certificates have been added to revocation list by Symbian.

This malware is discussed in our Lab Weblog:

Arrival

The worm spreads by sending text messages that contain variable messages in Chinese and a link to a website at 117.135.138.234. If the link is followed, an application will be installed promptly.

Execution

The malware will be registered to start on the phone boot up, and tries to connect to a website at http://rec[...]rzwxdsu.com over GPRS or 3G connection, infecting the phone and restarting the SMS spreading.

The worm has also been spread on different Chinese file sharing web sites in a file disguised as a game or theme for Symbian Series60 3rd & 5th edition phones.

Note

No report on this malware has been received outside of China.