Malware descriptions


New programs targeting mobile devices rarely hit the headlines anymore; we’ve got used to smartphone malware. But occasionally something comes along that stands out a bit: right now, it’s Trojan-SMS.WinCE.Sejweek.a, a new program designed to send SMS messages from an infected device. What makes it different from other SMS Trojans? Let’s take a look.

Most malware which sends SMS messages to premium-rate numbers use a number and a message text which are coded into the malware itself. Sejweek is a bit different though – when run, the Trojan tries to download an XML file to the smartphone from http://today*******.cn/*****/*****/get.php. At the time of writing, the file looked like this:

This file contains the premium-rate number (surrounded by the <phone> tag); the SMS text (<text>); and how long should elapse between each SMS message being sent (<interval>). Putting the number in a separate file, rather than in the malware itself, makes it easy to change the number if the first one gets blocked, extending the whole money-making cycle and maximizing profits.

If the XML file gets downloaded correctly, the malware decrypts “YGLYGLMKTYGL” and “YGLYGL” (i.e. the number SMSs get sent to, and the time between SMSs) and gets “1151” and “11”. In other words, messages saying 60*** are sent to the 1151 premium-rate number with an interval of 11 seconds between messages. With one SMS sent to 1151 costing around 40 roubles (a bit over $1) owners of infected devices will quickly start counting their losses!


Your email address will not be published. Required fields are marked *



Lyceum group reborn

According to older public researches, Lyceum conducted operations against organizations in the energy and telecommunications sectors across the Middle East. In 2021, we have been able to identify a new cluster of the group’s activity, focused on two entities in Tunisia.

GhostEmperor: From ProxyLogon to kernel mode

While investigating a recent rise of attacks against Exchange servers, we noticed a recurring cluster of activity that appeared in several distinct compromised networks. With a long-standing operation, high profile victims, advanced toolset and no affinity to a known threat actor, we decided to dub the cluster GhostEmperor.

APT trends report Q2 2021

This is our latest summary of advanced persistent threat (APT) activity, focusing on significant events that we observed during Q2 2021: attacks against Microsoft Exchange servers, APT29 and APT31 activities, targeting campaigns, etc.

Subscribe to our weekly e-mails

The hottest research right in your inbox