Malware descriptions

Trojan-SMS.WinCE.Sejweek

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!

Trojan-SMS.WinCE.Sejweek

Your email address will not be published.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

 

Reports

Lazarus targets defense industry with ThreatNeedle

In mid-2020, we realized that Lazarus was launching attacks on the defense industry using the ThreatNeedle cluster, an advanced malware cluster of Manuscrypt (a.k.a. NukeSped). While investigating this activity, we were able to observe the complete life cycle of an attack, uncovering more technical details and links to the group’s other campaigns.

Sunburst backdoor – code overlaps with Kazuar

While looking at the Sunburst backdoor, we discovered several features that overlap with a previously identified backdoor known as Kazuar. Our observations shows that Kazuar was used together with Turla tools during multiple breaches in past years.

Lazarus covets COVID-19-related intelligence

As the COVID-19 crisis grinds on, some threat actors are trying to speed up vaccine development by any means available. We have found evidence that the Lazarus group is going after intelligence that could help these efforts by attacking entities related to COVID-19 research.

Sunburst: connecting the dots in the DNS requests

We matched private and public DNS data for the SUNBURST-malware root C2 domain with the CNAME records, to identify who was targeted for further exploitation. In total, we analyzed 1722 DNS records, leading to 1026 unique target name parts and 964 unique UIDs.

Subscribe to our weekly e-mails

The hottest research right in your inbox