Hiding in plain sight: PhantomLance walks into a market

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In July 2019, Dr. Web reported about a backdoor trojan in Google Play, which appeared to be sophisticated and unlike common malware often uploaded for stealing victims’ money or displaying ads. So, we conducted an inquiry of our own, discovering a long-term campaign, which we dubbed “PhantomLance”, its earliest registered domain dating back to December 2015. We found dozens of related samples that had been appearing in the wild since 2016 and had been deployed in various application marketplaces including Google Play. One of the latest samples was published on the official Android market on November 6, 2019. We informed Google of the malware, and it was removed from the market shortly after.

During our investigation, we discovered various overlaps with reported OceanLotus APT campaigns. Thus, we found multiple code similarities with the previous Android campaign, as well as macOS backdoors, infrastructure overlaps with Windows backdoors and a few cross-platform resemblances.

Besides the attribution details, this document describes the actors’ spreading strategy, their techniques for bypassing app market filters, malware version diversity and the latest sample deployed in 2020, which uses Firebase to decrypt the malicious payload.

Our report is broken down into several sections.

1. Malware versions – technical description of versions found, their features and relationships between them.
   
2. Spread – information on specific tactics used by the threat actors for distributing their malware.
   
3. Infrastructure – further details on uncovered infrastructure pieces as well as overlaps found.
   
4. Victimology – thoughts on the actors’ interests in choosing their targets.
   
5. Overlaps with previous campaigns – details of similarities with all related campaigns that we have identified.
   

More information on PhantomLance is available to customers of Kaspersky Intelligence Reporting. For more information, contact intelreports@kaspersky.com

Malware versions

For the purposes of the research, we divided samples we found into a series of “versions” based on technical complexity: from the basic Version 1 to the highly sophisticated Version 3. Note that they do not fully correlate with the chronological order of their appearance ITW: for example, we observed Version 1 samples in late 2019 and in 2017, the year that we also saw Version 3.

Functionality of all samples are similar – the main purpose of spyware was to gather sensitive information. While the basic functionality was not very broad, and included geolocation, call logs, contact access and SMS access, the application could also gather a list of installed applications, as well as device information, such as model and OS version. Furthermore, the threat actor was able to download and execute various malicious payloads, thus, adapting the payload that would be suitable to the specific device environment, such as Android version and installed apps. This way the actor is able to avoid overloading the application with unnecessary features and at the same time gather information needed.

Version 1

We attribute the latest Google Play sample (MD5: 2e06bbc26611305b28b40349a600f95c) to this version. This is a clear payload, and unlike the other versions, it does not drop an additional executable file. Our main theory about the reasons for all these versioning maneuvers is that the attackers are trying to use diverse techniques to achieve their key goal, to bypass the official Google marketplace filters. And achieve it they did, as even this version passed Google’s filters and was uploaded to Google Play Store in 2019 (see Spreading for details).

No suspicious permissions are mentioned in the manifest file; instead, they are requested dynamically and hidden inside the dex executable. This seems to be a further attempt at circumventing security filtering. In addition to that, there is a feature that we have not seen before: if the root privileges are accessible on the device, the malware can use a reflection call to the undocumented API function “setUidMode” to get permissions it needs without user involvement.

Most of the aforementioned operations naturally require root access, but we believe that the root exploit may be delivered as payload in a server response to collected device info. Also, some of the applications that the malware mimics will have notified the user that they only work on rooted devices. For instance, Browser Cleaner can only clean up the browser cache if it is given root permissions.
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