Frequently Asked Questions:

General Questions

Can I analyze URLs with Cuckoo?

Yes you can. Since version 0.5 URLs are natively supported by Cuckoo. Additional details on how URL submissions is documented ../usage/submit.html#submission-utility.

$ ./utils/submit.py –url http://www.example.com

Can I use Volatility with Cuckoo?

Cuckoo 0.5 introduces support for optional full memory dumps, which are created at the end of the analysis process. You can use these memory dumps to perform additional memory forensic analysis with Volatility.

Please also consider that we don’t particularly encourage this: since Cuckoo employs some rootkit-like technologies to perform its operations, the results of a forensic analysis would be polluted by the sandbox’s components.

What do I need to use Cuckoo with VMware ESXi?

To run with VMware vSphere Hypervisor (or ESXi) Cuckoo leverages libvirt. Libvirt is currently using the VMware API to take control over virtual machines, though these APIs are available only in the licensed version. In VMware vSphere free edition, these APIs are read only, so you are unable to use Cuckoo with it. For the minimum license needed, please have a look at VMware website.


After upgrade Cuckoo stops to work

Probably you upgraded it in a wrong way. It’s not a good practice to rewrite the files due to Cuckoo’s complexity and quick evolution.

Please follow the upgrade steps described in Upgrade from a previous release.

Cuckoo stumbles and produces some error I don’t understand

Cuckoo is a mature but always evolving project, it’s possible that you encounter some problems while running it, but before you rush into sending emails to everyone make sure you read what follows.

Cuckoo is not meant to be a point-and-click tool: it’s designed to be a highly customizable and configurable solution for somewhat experienced users and malware analysts.

It requires you to have a decent understanding of your operating systems, Python, the concepts behind virtualization and sandboxing. We try to make it as easy to use as possible, but you have to keep in mind that it’s not a technology meant to be accessible to just anyone.

That being said, if a problem occurs you have to make sure that you did everything you could before asking for time and effort from our developers and users. We just can’t help everyone, we have limited time and it has to be dedicated to the development and fixing of actual bugs.

  • We have extensive documentation, read it carefully. You can’t just skip parts of it.
  • We have a mailing list archive, search through it for previous threads where your same problem could have been already addressed and solved.
  • We have a Community platform for asking questions, use it.
  • We have lot of users producing content on Internet, Google it.
  • Spend some of your own time trying fixing the issues before asking ours, you might even get to learn and understand Cuckoo better.

Long story short: use the existing resources, put some efforts into it and don’t abuse people.

If you still can’t figure out your problem, you can ask help on our online communities (see Final Remarks). Make sure when you ask for help to:

  • Use a clear and explicit title for your emails: “I have a problem”, “Help me” or “Cuckoo error” are NOT good titles.
  • Explain in details what you’re experiencing. Try to reproduce several times your issue and write down all steps to achieve that.
  • Use no-paste services and link your logs, configuration files and details on your setup.
  • Eventually provide a copy of the analysis that generated the problem.

Check and restore current snapshot with KVM

If something goes wrong with virtual machine it’s best practice to check current snapshot status. You can do that with the following:

$ virsh snapshot-current "<Name of VM>"

If you got a long XML as output your current snapshot is configured and you can skip the rest of this chapter; anyway if you got an error like the following your current snapshot is broken:

$ virsh snapshot-current "<Name of VM>"
error: domain '<Name of VM>' has no current snapshot

To fix and create a current snapshot first list all machine’s snapshots:

$ virsh snapshot-list "<Name of VM>"
 Name                 Creation Time             State
 1339506531           2012-06-12 15:08:51 +0200 running

Choose one snapshot name and set it as current:

$ snapshot-current "<Name of VM>" --snapshotname 1339506531
Snapshot 1339506531 set as current

Now the virtual machine state is fixed.

Check and restore current snapshot with VirtualBox

If something goes wrong with virtual it’s best practice to check the virtual machine status and the current snapshot. First of all check the virtual machine status with the following:

$ VBoxManage showvminfo "<Name of VM>" | grep State
State:           powered off (since 2012-06-27T22:03:57.000000000)

If the state is “powered off” you can go ahead with the next check, if the state is “aborted” or something else you have to restore it to “powered off” before:

$ VBoxManage controlvm "<Name of VM>" poweroff

With the following check the current snapshots state:

$ VBoxManage snapshot "<Name of VM>" list --details
Name: s1 (UUID: 90828a77-72f4-4a5e-b9d3-bb1fdd4cef5f)
Name: s2 (UUID: 97838e37-9ca4-4194-a041-5e9a40d6c205) *

If you have a snapshot marked with a star “*” your snapshot is ready, anyway you have to restore the current snapshot:

$ VBoxManage snapshot "<Name of VM>" restorecurrent

Unable to bind result server error

At Cuckoo startup if you get an error message like this one:

2014-01-07 18:42:12,686 [root] CRITICAL: CuckooCriticalError: Unable to bind result server on [Errno 99] Cannot assign requested address

It means that Cuckoo is unable to start the result server on the IP address written in cuckoo.conf (or in machinery.conf if you are using the resultserver_ip option inside). This usually happen when you start Cuckoo without bringing up the virtual interface associated with the result server IP address. You can bring it up manually, it depends from one virtualization software to another, but if you don’t know how to do, a good trick is to manually start and stop an analysis virtual machine, this will bring virtual networking up.

In the case of VirtualBox the hostonly interface vboxnet0 can be created as follows:

# If the hostonly interface vboxnet0 does not exist already.
$ VBoxManage hostonlyif create

# Configure vboxnet0.
$ VBoxManage hostonlyif ipconfig vboxnet0 --ip --netmask

Error during template rendering

Changed in version 2.0-rc1.

In our 2.0-rc1 release a bug was introduced that looks as follows in the screenshot below. In order to resolve this issue in your local setup, please open the web/analysis/urls.py file and modify the 21st line by adding an underscore as follows:

-        "/(?P<ip>[\d\.]+)?/(?P<host>[a-zA-Z0-9-\.]+)?"
+        "/(?P<ip>[\d\.]+)?/(?P<host>[ a-zA-Z0-9-_\.]+)?"

The official fixes for this issue can be found in the following commits.


501 Unsupported Method (‘GET’)

Changed in version 2.0-rc1.

Since 2.0-rc1 Cuckoo supports both the legacy Cuckoo Agent as well as a new, REST API-based, Cuckoo Agent for communication between the Guest and the Host machine. The new Cuckoo Agent is an improved Agent in the sense that it also allows usage outside of Cuckoo. As an example, it is used extensively by VMCloak in order to automatically create, configure, and cloak Virtual Machines.

Now in order to determine whether the Cuckoo Host is talking to the legacy or new Cuckoo Agent it does a HTTP GET request to the root path (/). The legacy Cuckoo Agent, which is based on xmlrpc, doesn’t handle that specific route and therefore returns an error, 501 Unsupported method.

Having said that, the message is not actually an error, it is simply Cuckoo trying to determine to which version of the Cuckoo Agent it is talking.


It should be noted that even though there is a new Cuckoo Agent available, backwards compatibility for the legacy Cuckoo Agent is still available and working properly.