The SonicWall Capture Labs Threat Research team observed reports of a new variant family of Mobef ransomware actively spreading in the wild.

The Mobef ransomware encrypts the victim’s files with a strong encryption algorithm just for fun.

Infection Cycle:

The ransomware adds the following files to the system:

• Malware.exe
  • %App.path%\ IMPORTANT.README
  • %App.path%\ SECRET.KEYFILE

Once the computer is compromised, the ransomware runs the following commands:

When Mobef is started it will create and assign a unique ID number to the victim then scan all local drives for data files to encrypt.

When encrypting files it will use the AES encryption algorithm and only encrypt those files that match the following extensions:

mp3, mp4, jpe, jpg, kdc, mdb, mdf, mef, mrw, nef, crt, crw, dbf, dcr, der, dng, doc, docm, docx, dwg, dxf, dxg, rwl, srf, srw, wb2, wpd, wps, xlk, nrw, odb, odm, odp, ods, odt, orf, p12, p7b, p7c, pdd, xls, xlsb, xlsm, xlsx, pef, pem, pfx, ppt, pptm, pptx, psd, pst, ptx, r3d, raf, raw, rtf.

Here is an example:

The ransomware encrypts all the without changing their extension filename.

After encrypting all personal documents, the ransomware shows the following image containing a message reporting that the computer has been encrypted just for fun.

 

SonicWall Capture Labs provides protection against this threat via the following signature:

• GAV: Mobef.RSM (Trojan)

This threat is also detected by SonicWALL Capture ATP w/RTDMI and the Capture Client endpoint solutions.

Updated January 15, 2021

The U.S. Department of Homeland Security (DHS) and the Cybersecurity and Infrastructure Security Agency (CISA) have confirmed that malicious threat actors have been and are actively exploiting vulnerabilities in SolarWinds Orion products, specifically affected versions 2019.4 through 2020.2.1 HF1.

 

The threat actor primarily leverages a malware commonly known as SUNBURST to conduct a global supply-chain attack against the SolarWinds Orion platform. SolarWinds Orion is an enterprise-grade IT monitoring solution.

 

This malware was seen being distributed as part of SolarWinds Orion software updates from March 2020.  As part of the software update, this malware comes in the form of a dynamic linked library (DLL) that was digitally signed by SolarWinds.  Once loaded by legitimate SolarWinds.BusinessLayerHost.exe or SolarWinds.BusinessLayerHostx64.exe, this malware is capable of transferring data, file execution, system profiling, rebooting and more.

 

Apart from being digitally signed, this malware employed other evasion tactics.  These include employing Teardrop, which is a memory only dropper, to deploy a customized Cobalt Strike beacon.  It also encoded strings such as domain names, user-agents, registry keys and others.

 

A few of the notable encoded strings are as follows:

• 583da945-62af-10e8-4902-a8f205c72b2e -> This is the name of a named pipe which will be used as a mutex to avoid multiple instances of the malware from running.
• avsvmcloud[.]com -> one of the domain names this malware connects to.
• SolarWindsOrionImprovementClient/3.0.0.382 -> the User-Agent field the malware will use during HTTP communication to the C&C Server

 

The Command & Control traffic is also difficult to detect as it was designed to mimic legitimate SolarWinds API calls.  Unlike other botnet malware which connects to their C&Cs in a regular basis, SUNBURST only communicates to the malicious server once every 12 to 14 days.

 

SolarWinds has confirmed the attack and has asked impacted customers using Orion to immediately upgrade to 2019.4 HF 6 or 2020.2.1 HF 1. Please visit www.solarwinds.com/securityadvisory for more information about your Orion upgrade options.

 

Both SolarWinds and the CISA strongly suggest that organizations using SolarWinds Orion verify the version they’re running and upgrade immediately, if required.

 

SonicWall Capture Labs threat researchers have investigated the vulnerability and published multiple signatures in different categories that identify malicious activity against affected SolarWinds Orion versions. It includes application identification signatures that detect if an organization has SolarWinds Orion deployed within its network; malicious domain signatures; malicious IPs; malware such as Sunburst, Supernova and Teardrop. These signatures are applied automatically to SonicWall firewalls with active security subscriptions.

Application signatures – identify SolarWinds Orion applications:

• 15296: BUSINESS-APPS SolarWinds Orion (API Activity)
• 2014: BUSINESS-APPS SolarWinds Orion (Update Activity)

IPS signatures – identify malicious domains:

• 15292: SolarWinds Supply Chain Malware Activity 1
• 15293: SolarWinds Supply Chain Malware Activity 2
• 15294: SolarWinds Supply Chain Malware Activity 3
• 15295: SolarWinds Supply Chain Malware Activity 4
• 15298: SolarWinds Supply Chain Malware Activity 5
• 15299: SolarWinds Supply Chain Malware Activity 6
• 15300: SolarWinds Supply Chain Malware Activity 7
• 15301: SolarWinds Supply Chain Malware Activity 8
• 15302: SolarWinds Supply Chain Malware Activity 9
• 15303: SolarWinds Supply Chain Malware Activity 10
• 15308: SolarWinds Supply Chain Malware Activity 11
• 15309: SolarWinds Supply Chain Malware Activity 12
• 15310: SolarWinds Supply Chain Malware Activity 13
• 15311: SolarWinds Supply Chain Malware Activity 14
• 15312: SolarWinds Supply Chain Malware Activity 15
• 15313: SolarWinds Supply Chain Malware Activity 16
• 15314: SolarWinds Supply Chain Malware Activity 17
• 15315: SolarWinds Supply Chain Malware Activity 18
• 15316: SolarWinds Supply Chain Malware Activity 19
• 15317: SolarWinds Supply Chain Malware Activity 20

GAV signatures – identify malwares: [Updated on Jan 14]

Sunburst – Backdoor malware that has been trojanized into multiple SolarWinds Orion update versions.

• SunBurst.A (Trojan) IOC:d0d626deb3f9484e649294a8dfa814c5568f846d5aa02d4cdad5d041a29d5600
• SolarWinds.DL (Trojan), IOC:ce77d116a074dab7a22a0fd4f2c1ab475f16eec42e1ded3c0b0aa8211fe858d6
• SunBurst.A_1 (Trojan), IOC:32519b85c0b422e4656de6e6c41878e95fd95026267daab4215ee59c107d6c77
• SunBurst.A_2 (Trojan), IOC:ad2fbf4add71f61173975989d1a18395afb8538ed889012b9d2e21c19e98bbd1
• SunBurst.A_3 (Trojan), IOC:019085a76ba7126fff22770d71bd901c325fc68ac55aa743327984e89f4b0134

Supernova – a webshell planted in the code of the Orion network and applications monitoring platform and enabled adversaries to run arbitrary code on machines running the trojanized versions of the software.

• Injector.DN_35 (Trojan) IOC:c15abaf51e78ca56c0376522d699c978217bf041a3bd3c71d09193efa5717c71
• Supernova.A_1 (Trojan), IOC:1c96021ac8cb52173e762f6b008fb4c6e5ef113e6baa4e2cf4848e88c61d9700

Teardrop – a memory only dropper that runs as a service

• Teardrop.B (Trojan), IOC:6e4050c6a2d2e5e49606d96dd2922da480f2e0c70082cc7e54449a7dc0d20f8d

Domain Blacklist: [Updated on Jan 15]

• avsvmcloud.com
• digitalcollege.org
• freescanonline.com
• deftsecurity.com
• thedoccloud.com
• virtualdataserver.com
• incomeupdate.com
• databasegalore.com
• panhardware.com

 

SonicWall products and real-time security services can help organizations identify and mitigate SUNBURST malware and other attacks against vulnerable SolarWinds Orion versions.

 

To verify you have the latest SonicWall Intrusion Prevention Signatures (IPS), please follow the steps in this knowledgebase (KB) article: https://www.sonicwall.com/support/knowledge-base/detailed-information-on-intrusion-prevention-signature-ips-signature-ids/170505742887527/

 

SonicWall Threats Research team came across an Android spyware that steals sensitive user information and sends it to the attacker. The app has a plethora of functionalities that are centered towards stealing information from the device. However a more concerning element of the malware is that all the stolen information is transmitted over an unsecured http channel.

Infection Cycle

Details of the sample analyzed:

• MD5:5c698417916ab2a9df1d577507be5725
• App Name: 19금 틱톡 (19 gold tiktok)
• Package Name: com.yjx.callservice

Upon installation the app is visible in the app drawer as follows:

Upon execution the app starts communicating with the attacker using the hardcoded IP 116.193.152.176:7788. The communication happens over http which indicates that any user information sent to the user is done so over an unsecured channel. One of the first things done by the app is creating a unique id for the infected device, this id is saved in the shared_prefs file locally and then shared with the attacker to report the initial infection. This is performed using a POST request to addNewUser as shown below:

The malware then sends the following data from the infected device:

• Contacts on the device are sent to addContactes (notice the spelling error):

• Apps installed are sent to addAppes (another spelling mistake):

 

There are additional interesting API requests present in the code that highlight the features and capabilities of this malware:

• addNewAccount
• addNewCallloges
• addNewLocation
• addNewSmses
• getAllBlackList
• editUserMobileNetwork
• findCall
• getRealPhone
• getAllIncoming
• uploadFile

 

Functionalities in the code

The malware is capable of communicating with the attacker using webSocket. The malware can execute the following functionality based on the code received via webSockets:

• take_photo

• start_record

There are additional traces in the code which reveal more functionality of the malware. It is capable of the following:

• Steal all the SMS on the device:

• Steal the call logs from the device:

• Steal all contacts:

• Get all apps installed on the device, we saw this functionality being used via network communication earlier:

 

Additional investigation

• A network graph of the attacker’s domain reveals two additional apps that communicate with it:

 

• The two apk’s related to this campaign have similar functionality. Below are the MD5’s:
  • e8509b2a57423a1b4b2d8bcf33973974
  • b67d42100440dd6c03b56da2c71b5130

 

• The hardcoded attacker’s  domain opens a login page. As mentioned before this happens over http, as a result any sensitive information can be further snooped by someone else:

 

• Following hardcoded information is present in the code:

Attacker server IP:

Gmail credentials:

QQ chat id:

Overall this malware is geared towards stealing sensitive user information from an infected device. The log messages and text present in the code is Korean, additionally the language used on the attacker’s server login is Korean as well.

 

SonicWall Capture Labs provide protection against this threat with the following signature:

• Banker.SP (Trojan)

Indicators of Compromise (IOC’s):

• 5c698417916ab2a9df1d577507be5725
• e8509b2a57423a1b4b2d8bcf33973974
• b67d42100440dd6c03b56da2c71b5130