My View on #Maze #Malware #Cognizant version #InfoSec

Krishnendu Paul

Apr 22, 2020 6 min read

Yes, it is a known story now that IT Giant #Congizant suffering from Maze Malare infection partly. Lot of their system got encrypted and hackers asking for Ransom !

There are other malwares, but one of the tactics used by Maze / ChaCha group to put pressure on their victim is to publish the data on the internet as leaked data. So, for a company like #Cognizant , who handles a lot of customers data - it is really business critical.

You can get the full detailed analysis my McAfee here

I will share few of my findings which may give some extra informations. Now, lets move to technical details. Following are the files of the infector

910aa49813ee4cc7e4fa0074db5e454a 4218214f32f946a02b7a7bebe3059af3dd87bcd130c0469aeb21b58299e2ef9a kepstl32.dll
76f8f28bd51efa03ab992fdb050c8382 5470f0644589685000154cb7d3f60280acb16e39ca961cce2c016078b303bc1b memes.tmp
b6786f141148925010122819047d1882 c84b2c7ec20dd835ece13d5ae42b30e02a9e67cc13c831ae81d85b49518387b9 maze.dll
11308e450b1f17954f531122a56fae3b 9845f553ae868cd3f8d8c3f8684d18f226de005ee6b52ad88b353228b788cf73 RANDOM

You can download all samples from here.

Download Maze Malware

Messege me , or break the password to get the files.

Till date, I found around 8-9 variants of the same malware. If you remember , there were huge hit on multiple English Speaking farm , on last 2019 by the same group. Last time they disclosed a 14.1 GB file containing data from various organization in underground Russian forum. And, recently on 2020, they release around 9.5 GB of data from few companies related to health sector.

Last time they infected using spams and fake application. But, this time it seems hot topic #Covid19 based email phishing campaigns. But, this time they deployed more complicated attack and persistance behaviour, including infecting recovery boot image. ( )

boot.sdi = Windows Deployment System Image.

It is overwritting C:\Recovery\XXXXXX-XXXXX-XXXXX-XXXXX\boot.sdi in my case. So, once you are infected, if you want to use recovery image to restore your PC - it will infect you again. Also, there are traces it is adding something in adobe acrobat directory as well


From behaviour, it seems it is exploiting following on a system

  • Adobe acrobat
  • Microsoft Office
  • Adobe Flash
  • Some mediaplayer - which is vulnerable on M4A and .FLV files.
  • Recovery Imgaes
  • RDP ( Remote Desktop )
  • Firefox
  • Chrome
  • Internet Explorer

It is having debug pdb set to  C:\Wuhan\Lab\coronashit.pdb . Previous version use to have different pdb path.

Also, it contains to resources ( already segricated as details.dll inside the zip file ) . And more confusing, in string table - having CHINESE HONGKONG as language. For note, previous community use to believe that it is from Russian Origin.

When going through the reversed code, came accross a section where it is checking for WY&WdhJSDIHGDjd.HSgshh file under C:\sf3\jytj43t\a33ewe\  folder and then exiting. Even if some researcher are pointing that as Kill Switch, but in my case it is not working, and also my thought is, it kept for a future version for something.

In static analysis it is on following Mitre Techniques

But, on dynamic analysis - actual game starts. It is having tremendous sandbox bypassing features included. It is waiting for more than 3 minutes before starting payloads. Also having debugger bypass as well. It is checking for CPU temp, system time etc.


Initial AccessExecutionPersistencePrivilege   EscalationDefense   EvasionCredential   AccessDiscoveryLateral   MovementCollectionExfiltrationCommand   and ControlNetwork   EffectsRemote   Service EffectsImpact
Valid AccountsWindows Management InstrumentationHidden Files and DirectoriesProcess InjectionMasqueradingCredential DumpingVirtualization/Sandbox EvasionApplication Deployment SoftwareMan in the BrowserData EncryptedStandard Cryptographic Protocol2Eavesdrop on Insecure Network CommunicationRemotely Track Device Without AuthorizationData Encrypted for Impact
Replication   Through Removable MediaRegsvr32Registry Run   Keys / Startup FolderAccessibility   FeaturesHidden Files   and DirectoriesNetwork   SniffingProcess   DiscoveryRemote ServicesData from Local   SystemExfiltration   Over Other Network MediumStandard   Non-Application Layer ProtocolExploit SS7 to   Redirect Phone Calls/SMSRemotely Wipe   Data Without AuthorizationDevice Lockout
External Remote ServicesGraphical User InterfaceAccessibility FeaturesPath InterceptionVirtualization/Sandbox EvasionInput CaptureSecurity Software DiscoveryWindows Remote ManagementData from Network Shared DriveAutomated ExfiltrationStandard Application Layer ProtocolExploit SS7 to Track Device LocationObtain Device Cloud BackupsDelete Device Data
Drive-by   CompromiseScheduled TaskSystem FirmwareDLL Search   Order HijackingProcess   InjectionCredentials in   FilesFile and   Directory DiscoveryLogon ScriptsInput CaptureData EncryptedConnection   ProxySIM Card SwapPremium SMS   Toll Fraud
Exploit Public-Facing   ApplicationCommand-Line InterfaceShortcut ModificationFile System Permissions WeaknessRegsvr32Account ManipulationSystem Information DiscoveryShared WebrootData StagedScheduled TransferStandard Cryptographic ProtocolManipulate Device CommunicationManipulate App Store Rankings or Ratings
Spearphishing   LinkGraphical User   InterfaceModify Existing   ServiceNew ServiceFile DeletionBrute ForceSystem   Owner/User DiscoveryThird-party   SoftwareScreen CaptureData Transfer   Size LimitsCommonly Used   PortJamming or   Denial of ServiceAbuse   Accessibility Features
Spearphishing AttachmentScriptingPath InterceptionScheduled TaskDLL Side-LoadingTwo-Factor Authentication InterceptionNetwork SniffingPass the HashEmail CollectionExfiltration Over Command and Control ChannelUncommonly Used PortRogue Wi-Fi Access PointsData Encrypted for Impact
Spearphishing   via ServiceThird-party   SoftwareLogon ScriptsProcess   InjectionConnection   ProxyBash HistoryNetwork Service   ScanningRemote Desktop   ProtocolClipboard DataExfiltration   Over Alternative ProtocolStandard   Application Layer ProtocolDowngrade to   Insecure ProtocolsGenerate   Fraudulent Advertising Revenue

Total URLs found on all version of Maze Malware including latest variants: of domains associated with Maze.txt

And if you need PCAP of network activities, here you are:

It also delete all shadow copies

C:\Windows\System32\wbem\WMIC.exe 'C:\assa\pcccc\..\..\Windows\ncd\..\system32\grkn\wpxrq\..\..\wbem\bbup\ott\yf\..\..\..\wmic.exe' shadowcopy delete

I am very confused about lateral movement once they infected one system inside #Cognizant. I didn't found any wormable exploit inbuild, only RDP and share folder access bruteforce and password dumping !! It can not be a good reason for smooth lateral movement inside a company like #Cognizant have more than 200,000+ employees worldwide. Then - I found following. As per my source, forum thread opened on 11th April, 2020 and then closed on 15th April, 2020. And then Cognizant Incident happened.

Is it the same company ? What do you think ? Please let me know in comment !

Seems they are exploiting following vulnerabilities for privilage escalation:

  • CVE-2016-7255
  • CVE-2018-8453

URLs accessed using POST

As per my intel "encrypted computer keys are hidden inside NTFS metadata, by using Extended Attributes. An empty file is created, %ProgramData%\0x29A.db and a custom extended attribute named KREMEZ is set to that file" . Even if that's the decryption key, you need private master key to decrypt that key.


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