PA-3050 detected dns queries to malicious URL but all other anti-malware detected none

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Highlighted
L1 Bithead

PA-3050 detected dns queries to malicious URL but all other anti-malware detected none

The Palo Alto device is saying that a workstation on the network is querying the DNS server for some malicious URLs for some of the dates and some of the time.

Full scan using McAfee VSE, Microsoft Safety Scanner, Malwarebytes, Spybot, said no malware detected.

Using McAfee Getsusp I upload 40 suspicious and unknown files, analysed in McAfee lab – no malware detected. McAfee put these files under Virus Total, antivirus from 57 different vendors all say ‘clean’.

 

The log that says detection of malicious URL:

Receive TimeThreat/Content TypeGenerate TimeRuleApplicationVirtual SystemSource ZoneDestination ZoneSource PortDestination PortIP ProtocolActionURLThreat/Content NameCategorySeverityDirection 
12/3/2017 13:56spyware12/3/2017 13:56POC Alert Alldnsvsys1TapZone2TapZone25530553udpalert P2P-Worm.palevo:brero.balkan-hosting.net(3839431)anymediumclient-to-server
12/3/2017 13:56spyware12/3/2017 13:56POC Alert Alldnsvsys1TapZone2TapZone25530553udpalert Suspicious DNS Query (P2P-Worm.palevo:brero.balkan-hosting.net)(4022349)anymediumclient-to-server
12/3/2017 13:56spyware12/3/2017 13:56POC Alert Alldnsvsys1TapZone2TapZone25530553udpalert P2P-Worm.palevo:brero.balkan-hosting.net(3839431)anymediumclient-to-server
12/3/2017 13:56spyware12/3/2017 13:56POC Alert Alldnsvsys1TapZone2TapZone25530553udpalert Suspicious DNS Query (P2P-Worm.palevo:brero.balkan-hosting.net)(4022349)anymediumclient-to-server

I really don't know how to close this case. Who is right and how to prove either of the anti-malware wrong?

The workstation in question is a Windows 7 machine, the whole network is isolated (meaning no Internet access). The DNS server is Windows 2012, it is AD-integrated, no access to Internet. The workstation has McAfee VSE 8.8 and is definitions updated everyday. It also has McAfee HIPS, Solidcore, DLP and RSD.

Highlighted
L7 Applicator

Re: PA-3050 detected dns queries to malicious URL but all other anti-malware detected none

If this is something that is happening repeatedly, you could use a tool like "Microsoft Message Analyzer" to try and map the process on the Windows 7 system making the DNS query for the suspicious domain.  

 - https://www.microsoft.com/en-us/download/details.aspx?id=44226  (download link)

 - https://technet.microsoft.com/en-us/library/jj649776.aspx  (operating guide)

 

I will say that the Microsoft Message Analyzer is a very powerful tool (translate: difficult to use).  In fumbling around with it I was able to map a DNS lookup (mail server) to the requesting process (outlook.exe) - but don't ask me how I did it.  

 

If anyone has a better method of mapping a client DNS lookup to a specific process, I'd love to hear about it.  Good luck.  

Highlighted
L1 Bithead

Re: PA-3050 detected dns queries to malicious URL but all other anti-malware detected none

Thanks. I had actually used Microsoft Message Analyzer to try to capture any DNS query traffic but after 3 days of sniffing I wasn't able to capture anything, no dns query at all. So, there must be something I didn't do correctly or the software need something special action.

Highlighted
Cyber Elite

Re: PA-3050 detected dns queries to malicious URL but all other anti-malware detected none

@SingChung,

One thing that I would look at in the logs is what exactly the URL is that they are trying to access. I would say that most of the alerts that I recieve from this are generated by the user navigating to a website with less than perfect advertisement sources. If that doesn't work then Message Analyzer is probably your best bet, but it is a very very difficult tool to actually understand how to use. 

If all else fails make the user use another machine temporarly, say a day or two, so that you can 'look' at their current machine. See if the alerts change to the new machine or not; that would at least tell you if it's something they are doing or if it's truly a machine action. 

Highlighted
L1 Bithead

Re: PA-3050 detected dns queries to malicious URL but all other anti-malware detected none

BPry,

 

From the log, I guess these are the URLs:

brero.balkan-hosting.net

banjalucke-ljepotice.ru

 

The enironment is isolated, the user won't be able to go Internet. Therefore it is unlikely that the user has access website that contains hiding malicious advertisements.

 

The machine is already put offline and user not using it. I am currently working on a virtual clone of the machine in my Hyper-V environment. So, far I can't find anything suspicious on the machine.

 

Is it that there is no possibility the Palo Alto device is generating false positives?

 

Highlighted
L1 Bithead

Re: PA-3050 detected dns queries to malicious URL but all other anti-malware detected none

I analyzed the user logon and logoff events, I notice something interesting.

The Palo Alto detection has some relationship with user logon events. Whenever there is a interactive logon (at console or rdp), it was followed by a 3 minutes detection of malicious URL dns queries. The machine itself we can safely say no malware. The funny part is why there is always a detection for 3 minutes of same pattern whenever a user logs on. A check in Windows scheduler, these are programs that are scheduled to launch whenever a user logons on: Lenovo Solution Center, Lenovo Message Center Plus, Office Telemetry Agent, Realtek Lenovo MICPKey, Realtek Control Panel.

 

If user logs on but logoff in 2 minutes, it won't detect such malicious query (probably because the scheduled programs haven't finished starting up). So, it is evidence that one or more of these logon starting programs is doing some dns queries when starting up (perhaps to check for updates) but Palo Alto device read them as malicious. 

 

Is there a way for me to prove if the detections were indeed false positives?

Highlighted
Cyber Elite

Re: PA-3050 detected dns queries to malicious URL but all other anti-malware detected none

@SingChung,

You would need to capture the URL requests that the machine is actually using something like Fiddler2 or a debugging proxie like Charles Web Debugging Proxy. I would say that it probably isn't a false positive. It's pretty simple for the Palo Alto to read the URL that was requested, so you don't usually actually see false positives with URL detection. 

Highlighted
L1 Bithead

Re: PA-3050 detected dns queries to malicious URL but all other anti-malware detected none

I managed to capture the malicious dns query. I enable the dns client event logging, logged off, then log on. The event id 1015:

_______________________________________________________________________________________________________________

- System

- Provider

[ Name] Microsoft-Windows-DNS-Client
[ Guid] {1C95126E-7EEA-49A9-A3FE-A378B03DDB4D}

EventID 1015

Version 0

Level 4

Task 0

Opcode 0

Keywords 0x8000000000000000

- TimeCreated

[ SystemTime] 2017-12-26T02:28:55.443725400Z

EventRecordID 712

Correlation

- Execution

[ ProcessID] 1468
[ ThreadID] 4328

Channel Microsoft-Windows-DNS-Client/Operational

Computer (removed due to confidentiality)

- Security

[ UserID] S-1-5-20

- EventData

QueryName kreten.banjalucke-ljepotice.ru
AddressLength 28
Address 170000350000000024063003200200055AEF68FFFE249F2600000000

________________________________________________________________________________________

 

I can track down to process DNS Client as the querying process. unable to track which process asked the DNS client to do the query.

 

From the timing of the query, and the running of the scheduled tasks triggered by user logon, there are only these possibilities:

1. HotStart

2. CacheTask

3. OfficeTelemetryAgentLogOn

4. SystemSoundsService

 

All these are Microsot system tasks.

 

Highlighted
Cyber Elite

Re: PA-3050 detected dns queries to malicious URL but all other anti-malware detected none

@SingChung,

Scheduled tasks can be hijacked fairly easily. I would actually audit the task and make sure that they don't include a new call to this domain; my guess would be that the task itself has been hijacked and is now doing something with that domain. 

Highlighted
Cyber Elite

Re: PA-3050 detected dns queries to malicious URL but all other anti-malware detected none

@SingChung,

You might want to check out this as well. It directly references that URL, along with showing the Reg keys that it creats in Winlogon. Might want to verify that it isn't what you are looking for. 

 

https://www.sophos.com/en-us/threat-center/threat-analyses/viruses-and-spyware/W32~Palev-Gen/detaile...

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