CyberOps Associate Skills Assessment Answers – CA v1.0 Skills Exam

CyberOps Associates v1.0 – Skills Assessment


You have been hired as a junior security analyst. As part of your training, you were tasked to determine any malicious activity associated with the Pushdo trojan.

You will have access to the internet to learn more about the events. You can use websites, such as VirusTotal, to upload and verify threat existence.

The tasks below are designed to provide some guidance through the analysis process.

You will practice and be assessed on the following skills:

  • Evaluate event alerts using Squil and Kibana.
  • Use Google search as a tool to obtain intelligence on a potential exploit.
  • Use VirusTotal to upload and verify threat existence.

Content for this assessment was obtained from and is used with permission. We are grateful for the use of this material.

Required Resources

  • Host computer with at least 8GB of RAM and 45GB of free disk space
  • Latest version of Oracle VirtualBox
  • Security Onion virtual machine requires 4GB of RAM using 25GB disk space
  • Internet access


Part 1: Gather the Basic Information

In this part, you will review the alerts listed in Security Onion VM and gather basic information for the interested time frame.

Step 1: Verify the status of services

a. Log into Security Onion VM using with the username analyst and password cyberops.

b. Open a terminal window. Enter the sudo so-status command to verify that all the services are ready.

Right click Desktop backgroud, go to Open Terminal

analyst@SecOnion:~$ sudo so-status
Status: securityonion
  * sguil server                                                       [  OK  ]
Status: seconion-import
  * pcap_agent (sguil)                                                 [  OK  ]
  * snort_agent-1 (sguil)                                              [  OK  ]
  * barnyard2-1 (spooler, unified2 format)                             [  OK  ]
Status: Elastic stack
  * so-elasticsearch                                                   [  OK  ]
  * so-logstash                                                        [  OK  ]
  * so-kibana                                                          [  OK  ]
  * so-freqserver                                                      [  OK  ]

c. When the nsm service is ready, log into Sguil or Kibana with the username analyst and password cyberops.
Open Sguil using the shortcut on the Desktop. Login with the username analyst and password cyberops. Click Select All to select the interfaces and then Start SGUIL.

Step 2: Gather basic information.

a. Identify time frame of the Pushdo trojan attack, including the date and approximate time.
2017-06-27 from 13:38:34 to 13:44:32

b. List the alerts noted during this time frame associated with the trojan.

ET CURRENT_EVENTS WinHttpRequest Downloading EXE
ET POLICY PE EXE or DLL Windows file download HTTP
ET POLICY PE EXE or DLL Windows file download HTTP
ET CURRENT_EVENTS Terse alphanumeric executable downloader high likelihood of being hostile
ET POLICY PE EXE or DLL Windows file download HTTP
ET POLICY External IP Lookup Domain (myip.opendns .com in DNS lookup)
ET TROJAN Backdoor.Win32.Pushdo.s Checkin
ET TROJAN Pushdo.S CnC response
ET POLICY TLS possible TOR SSL traffic

c. List the internal IP addresses and external IP addresses involved.

Internal IP address:


External IP addresses:


Part 2: Learn about the Exploit

In this part, you will learn more about the exploit.

Step 1: Infected host

a. Based on the alerts, what is the IP and MAC addresses of the infected computer? Based on the MAC address, what is the vendor of the NIC chipset? (Hint: NetworkMiner or internet search)
MAC: 00-15-C5-DE-C7-3B
NIC Vendor: Dell Inc.

Explanation: Right-click Alert ID: 5410 –> Select NetworkMiner.

b. Based on the alerts, when (date and time in UTC) and how was the PC infected? (Hint: Enter the command date in the terminal to determine the time zone for the displayed time)
2017-06-27 13:38:32 UTC
The gerv.gun malware was executed through the Pushdo trojan.

On NetworkMiner windows, click Files tab to determine date and time in UTC:

How did the malware infect the PC? Use an internet search as necessary.

The user in the PC accessed a malicious domain, and the Pushdo trojan was used to install the malware.
Pushdo is a “downloader” trojan, meaning its purpose is to download and install additional malicious software. When executed, Pushdo reports back to one of several control server IP addresses embedded in it code. The server listens on TCP port 80, and pretends to be an Apache webserver. If the HTTP request contains the correct parameters, one or more executabl es will be delivered via HTTP. The malware to be downloaded by Pushdo depends on the value following the”s-underscore” part of the URL

Pushdo keeps track of the IP address of the victim, whether or not that person is an administator on the computer, their primary hard drive serial number (obtained by SMART_RCV_DRIVE_DATA IO control code), whether the filesystem is NTFS, how many times the victim system ha s executeda Pushdo variant, and the Windows OS version as returned by the GetVersionEx API call.

Step 2: Examine the exploit.

a. Based on the alerts associated with HTTP GET request, what files were downloaded? List the malicious domains observed and the files downloaded.

gerv.gun –
trow.exe –
wp.exe –

Explanation: Right-click Alert ID: 5410 –> Select Transcript

Right-click Alert ID: 5420 –> Select Transcript

Right-click Alert ID: 5421 –> Select Transcript

Use any available tools in Security Onion VM, determine and record the SHA256 hash for the downloaded files that probably infected the computer?

gerv.gun = 0931537889c35226d00ed26962ecacb140521394279eb2ade7e9d2afcf1a7272
trow.exe = 94a0a09ee6a21526ac34d41eabf4ba603e9a30c26e6a1dc072ff45749dfb1fe1
wp.exe = 79d503165d32176842fe386d96c04fb70f6ce1c8a485837957849297e625ea48

Explanation: Use NetworkMiner tool:
Right-click Alert ID: 5410 –> Select NetworkMiner –> Click Files tab –> Right click first line –> Select Calculate MD5 / SHA1 / SHA256 hash

Do the same for Alert ID: 5420 and 5421 to determine SHA256 hash for the files: trow.exe and wp.exe

b. Navigate to input the SHA256 hash to determine if these were detected as malicious files. Record your findings, such as file type and size, other names, and target machine. You can also include any information that is provided by the community posted in VirusTotal.


  • 58 engines detected this file
  • File type: Win32 EXE
  • File size: 236.00 KB (241664 bytes)
  • Names:
    • gerv.gun
    • test
    • tmp523799.697
    • tmp246975.343
    • tmp213582.420
    • extract-1498570714.111294-HTTP-FG0jno3bJLiIzR4hrh.exe
    • 0931537889c35226d00ed26962ecacb140521394279eb2ade7e9d2afcf1a7272.bin
  • Target Machine: Intel 386 or later processors and compatible processors


  • 63 engines detected this file
  • File type: Win32 EXE
  • File size: 323.00 KB (330752 bytes)
  • Names:
    • Pedals
    • Pedals.exe
    • trow.exe
    • test3
    • 2017-06-28_18-18-14.exe
    • bma2beo4.exe
  • Target Machine: Intel 386 or later processors and compatible processors


  • 55 engines detected this file
  • File type: Win32 EXE
  • File size: 300.50 KB (307712 bytes)
  • Names:
    • wp.exe
    • test2
    • test_3
    • 4da48f6423d5f7d75de281a674c2e620.virobj
    • wp.exe.x-msdownload
  • Target Machine: Intel 386 or later processors and compatible processors

Explanation:Open Chromium Web Browser –> access to –> Click Search –> Enter Hash

c. Examine other alerts associated with the infected host during this timeframe and record your findings

ET POLICY External IP Lookup Domain (myip.opendns .com in DNS lookup) – infection started when the user of the host performed a DNS lookup through a malicious domain – destination IP:

Step 3: Report Your Findings

Summarizes your findings based on the information you have gathered from the previous parts, summarize your findings.

The host with IP, a PC running Windows, accessed a malicious domain for a DNS query, and was infected with the Pushdo trojan. The Pushdo trojan pretends to be an Apache webserver, listening on port 80. After infection, the Pushdo trojan downloads various malware. In the examined PC, three malwares were downloaded and installed – gerv.gun, trow.exe and wp.exe. These files were checked in, using their SHA256 hash, and verified as malware by most source.

Download .ova files:

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1 year ago

Hi , Currently completing this but could you explain how we know the attack began at 13.38 even tho the malicious domain wasnt accesed til after this time ?Many thanks

Rajesh soni
Rajesh soni
2 years ago

can anyone please share the answer sheet for the reference on this email, [email protected]. I’m struggling to answer the question in report and supporting findings. Any help is much appreciated. thanks

Marcos Renato Rocha de Medeiros
Marcos Renato Rocha de Medeiros
2 years ago

I think you’re trying on the wrong date because even in the earliest print-screen, the date is 2017-06-27. And if you make a query with that date on Sguil you’ll notes that the event correlated to pushdo trojan occurs between 13:38 e 13:45

2 years ago

Can someone please send me your answer for comparison? My email is [email protected]

2 years ago

When the instructor mode will publish?

2 years ago

Do you know when it will be published? More or less than 2 weeks?