Analysis by: Christopher Daniel So

ALIASES:

Mal/PerlBot-A (Sophos), Backdoor.Perl.Shellbot.F (F-Secure), Perl:Shellbot-O [Trj] (Avast)

 PLATFORM:

Windows, UNIX, Linux

 OVERALL RISK RATING:
 DAMAGE POTENTIAL:
 DISTRIBUTION POTENTIAL:
 REPORTED INFECTION:
 INFORMATION EXPOSURE:

  • Threat Type: Backdoor

  • Destructiveness: No

  • Encrypted: No

  • In the wild: Yes

  OVERVIEW

Infection Channel: Dropped by other malware, Downloaded from the Internet

This malware is involved in the Bash Vulnerability Exploit attack of September 2014. It is capable of compromising an affected system's security by carrying out commands made by a malicious remote user.

To get a one-glance comprehensive view of the behavior of this Backdoor, refer to the Threat Diagram shown below.

This backdoor arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.

It joins an Internet Relay Chat (IRC) channel.

  TECHNICAL DETAILS

File Size: 38,453 bytes
File Type: Script
Memory Resident: Yes
Initial Samples Received Date: 26 Sep 2014
Payload: Compromises system security, Connects to URLs/IPs

Arrival Details

This backdoor arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.

Backdoor Routine

This backdoor connects to any of the following IRC server(s):

  • {BLOCKED}i.bot.nu:5190

It joins any of the following Internet Relay Chat (IRC) channels:

  • #nrpe

It accesses a remote Internet Relay Chat (IRC) server where it receives the following commands from a remote malicious user:

  • join - Join a channel
  • part - Leave a channel
  • rejoin - Leave and rejoin a channel
  • op - Grant a user an operator status
  • deop - Revoke a users operator status
  • voice - Grant a user an voice status
  • devoice - Revoke a users voice status
  • nick - Change nickname
  • msg - Send a private message
  • quit - Disconnect from the IRC server
  • raw - Send raw data to the IRC server
  • die - Terminate itself
  • udp1, udp2, udp3 - Perform UDP flooding
  • tcp - Perform TCP flooding
  • http - Perform HTTP flooding
  • ctcpflood - Send 20 IRC private messages to a target
  • msgflood - Send a long IRC private message to a target
  • noticeflood - Send two long IRC notice messages to a target
  • cback - Execute a remote shell (/bin/sh or cmd.exe)
  • download - Download from a URL and save to a specified file
  • portscan - Scans an IP address for the following ports: 1, 7, 9, 14, 20, 21, 22, 23, 25, 53, 80, 88, 110, 112, 113, 137, 143, 145, 222, 333, 405, 443, 444, 445, 512, 587, 616, 666, 993, 995, 1024, 1025, 1080, 1144, 1156, 1222, 1230, 1337, 1348, 1628, 1641, 1720, 1723, 1763, 1983, 1984, 1985, 1987, 1988, 1990, 1994, 2005, 2020, 2121, 2200, 2222, 2223, 2345, 2360, 2500, 2727, 3130, 3128, 3137, 3129, 3303, 3306, 3333, 3389, 4000, 4001, 4471, 4877, 5252, 5522, 5553, 5554, 5642, 5777, 5800, 5801, 5900, 5901, 6062, 6550, 6522, 6600, 6622, 6662, 6665, 6666, 6667, 6969, 7000, 7979, 8008, 8080, 8081, 8082, 8181, 8246, 8443, 8520, 8787, 8855, 8880, 8989, 9855, 9865, 9997, 9999, 10000, 10001, 10010, 10222, 11170, 11306, 11444, 12241, 12312, 14534, 14568, 15951, 17272, 19635, 19906, 19900, 20000, 21412, 21443, 21205, 22022, 30999, 31336, 31337, 32768, 33180, 35651, 36666, 37998, 41114, 41215, 44544, 45055, 45555, 45678, 51114, 51247, 51234, 55066, 55555, 65114, 65156, 65120, 65410, 65500, 65501, 65523, 65533
  • mail - Send an email to a target
  • port - Open a connection to a specified IP address and port
  • dns - Resolve an address to its IP address

NOTES:

If a command line parameter exists, it uses the first one as the IRC server instead of {BLOCKED}i.bot.nu:5190.

It chooses a randpom nickname from the following:

  • abbore
  • ably
  • abyss
  • acrima
  • aerodream
  • afkdemon
  • ainthere
  • alberto
  • alexia
  • alexndra
  • alias
  • alikki
  • alphaa
  • alterego
  • alvin
  • ambra
  • amed
  • andjela
  • andreas
  • anja
  • anjing
  • anna
  • apeq
  • arntz
  • arskaz
  • as
  • asmodizz
  • asssa
  • athanas
  • aulis
  • aus
  • bar
  • bast
  • bedem
  • beeth
  • bella
  • birillo
  • bizio
  • blackhand
  • blacky
  • blietta
  • blondenor
  • blueangel
  • bluebus
  • bluey
  • bobi
  • bopoh
  • borre
  • boy
  • bram
  • brigitta
  • brio
  • brrrweg
  • brujah
  • caprcorn
  • carloto
  • catgirl
  • cathren
  • cemanmp
  • chainess
  • chaingone
  • chck
  • chriz
  • cigs
  • cintat
  • clarissa
  • clbiz
  • clex
  • cobe
  • cocker
  • coke
  • colin
  • conan
  • condoom
  • coop
  • coopers
  • corvonero
  • countzero
  • cracker
  • cread
  • crnaruka
  • cruizer
  • cubalibre
  • cure
  • custodes
  • dan
  • dangelo
  • danic
  • daniela
  • dario
  • darker
  • darknz
  • davide
  • daw
  • demigd
  • des
  • devastor
  • diabolik
  • dimkam
  • dital
  • djtt
  • dogzzz
  • dolfi
  • dolphin
  • dottmorte
  • dracon
  • dragon
  • drtte
  • dumbblnd
  • dusica
  • ebe
  • edgie
  • eggist
  • einaimou
  • elef
  • elly
  • emmi
  • encer
  • engerim
  • erixon
  • eurotrash
  • fairsight
  • fin
  • fireaway
  • fjortisch
  • floutti
  • fluffer
  • flum
  • forever
  • fqw
  • fra
  • freem
  • freew
  • freud
  • funny
  • furia
  • furunkuli
  • fwsmou
  • gad
  • gamppy
  • gerhard
  • ghostie
  • gili
  • girlie
  • giugno
  • gizmo
  • glidaren
  • gold
  • gomora
  • gracie
  • grave
  • graz
  • grron
  • gsund
  • gufoao
  • hali
  • hallas
  • hammer
  • harri
  • harry
  • hayes
  • hazor
  • herbiez
  • hlios
  • hoffi
  • honeii
  • hongkong
  • hug
  • iasv
  • ibanez
  • ibanz
  • ibar
  • igi
  • illusins
  • imp
  • inkworks
  • iplord
  • ivan
  • ja
  • jaffa
  • jaimeafk
  • james
  • jamezdin
  • janet
  • janne
  • jason
  • javagrl
  • jayc
  • jazz
  • jejborta
  • jester
  • jj
  • jn
  • jockey
  • joe
  • joelbitar
  • johannes
  • johndow
  • johnny
  • joni
  • jonni
  • jornx
  • joshua
  • jossumi
  • judy
  • juge
  • juha
  • juhas
  • julze
  • juutsu
  • kajman
  • kalca
  • kamileon
  • kardinal
  • kasandra
  • katarina
  • kaviee
  • kbee
  • ken
  • keung
  • kewin
  • khan
  • kikeli
  • kikii
  • kilroi
  • kiwi
  • klaara
  • kliimax
  • klimas
  • kode
  • kojv
  • koopal
  • kralj
  • krash
  • krista
  • kronos
  • ktx
  • kungen
  • kuppa
  • kurai
  • lala
  • lamour
  • latina
  • legend
  • lenisaway
  • lily
  • linda
  • lingyee
  • linux
  • lisa
  • lisha
  • litta
  • littleboy
  • liverpoo
  • liyen
  • liz
  • liza
  • lonely
  • lonelygal
  • lonewolf
  • lopez
  • lordie
  • lovebyte
  • lph
  • luarbiasa
  • lucignol
  • lullaby
  • lunatic
  • luny
  • lupo
  • mac
  • macesgl
  • madd
  • mailman
  • malkav
  • malr
  • mamakians
  • mamaw
  • manarimou
  • manarisou
  • maradona
  • marakana
  • marco
  • marillion
  • mark
  • mary
  • master
  • maurino
  • max
  • mcalcota
  • melanie
  • melinda
  • meph
  • mephisto
  • mg
  • mhj
  • mhz
  • mig
  • miina
  • mika
  • mikav
  • mike
  • mikemcgii
  • mikko
  • mikma
  • mimma
  • miss
  • moladmin
  • monikaw
  • monkeyboy
  • monroe
  • monstop
  • mooks
  • mordeshur
  • mpdike
  • mrbate
  • mrbeauty
  • mrblom
  • mrbx
  • mrjee
  • mro
  • mrtabizy
  • mrx
  • mrxx
  • msd
  • mu
  • muimui
  • musashi
  • musc
  • musce
  • musicgal
  • muti
  • myboy
  • mystr
  • mythic
  • mywife
  • nallllle
  • nanask
  • natalie
  • natborta
  • ncubus
  • neutrino
  • niceguy
  • nico
  • niklas
  • nimfa
  • nino
  • nurul
  • obiwanbip
  • ogre
  • olivia
  • omega
  • only
  • orac
  • orace
  • oranzzzzz
  • organza
  • ourlove
  • outworld
  • outzake
  • oxygn
  • paliadog
  • pazarac
  • permaloso
  • perroz
  • pessaar
  • phre
  • phreaky
  • pihkal
  • pinball
  • poesje
  • poison
  • poofie
  • popy
  • powerpc
  • pper
  • primera
  • primetime
  • proxyma
  • pshyche
  • psioncore
  • psiximou
  • psixisou
  • psychosis
  • psyidle
  • pszaah
  • puppetm
  • pzzzz
  • quattro
  • question
  • ra
  • ragio
  • ragnetto
  • raiden
  • raindance
  • raistln
  • ranu
  • raska
  • raul
  • raye
  • reartu
  • red
  • reflect
  • ribica
  • richard
  • rick
  • rigo
  • rikuta
  • rikuxr
  • rita
  • rix
  • rob
  • roku
  • ronaldo
  • ronwrl
  • roticanai
  • rugiada
  • ruthless
  • saalut
  • sammi
  • sand
  • satanins
  • schzsh
  • scorpin
  • sealink
  • sean
  • secret
  • serpentor
  • servant
  • sethi
  • sexbolek
  • sexyman
  • sharmm
  • shearer
  • shekel
  • shio
  • shortys
  • shred
  • sidewalk
  • sil
  • siren
  • skar
  • skill
  • skru
  • sky
  • skygun
  • skylink
  • slaktarn
  • slash
  • slgon
  • smarties
  • smck
  • snake
  • snike
  • snoopgirl
  • sodoma
  • sopocani
  • sorceress
  • spacebbl
  • spacedump
  • spanker
  • spermboy
  • spirtouli
  • srk
  • stazzz
  • steve
  • stinga
  • stj
  • stjf
  • studenica
  • stussy
  • suez
  • suhoj
  • sukun
  • sunsola
  • surfer
  • sutera
  • svearike
  • sweetii
  • sweetlady
  • sweklopi
  • swepilot
  • switch
  • syncphos
  • szern
  • takumura
  • tallaxlc
  • tampone
  • tarabas
  • tatano
  • tato
  • tennis
  • tenx
  • terence
  • terkukur
  • tero
  • thefox
  • thesint
  • timer
  • timewalk
  • tmhd
  • tnxfck
  • to
  • tomihki
  • tommy
  • topo
  • triumph
  • trustme
  • tungau
  • tupac
  • turbozzzz
  • turing
  • tvrdjava
  • tysn
  • unicron
  • uoff
  • uptimer
  • utopia
  • vader
  • vaismi
  • vajje
  • vanda
  • varjo
  • vass
  • vento
  • venusguy
  • vertie
  • viagara
  • vicious
  • vidxxx
  • virex
  • vodafone
  • vone
  • vrgnie
  • vuubeibe
  • wanderer
  • warrr
  • wasabboy
  • weebee
  • wellu
  • wendy
  • whiskey
  • willgood
  • wing
  • winny
  • wknight
  • wlly
  • wolfman
  • wow
  • wp
  • xarasou
  • xtreme
  • xxx
  • xzone
  • yakzr
  • yang
  • yashy
  • yasin
  • yenyen
  • ykbug
  • yogiebear
  • zai
  • zfstr
  • zinj
  • zizu
  • zvezda
  • zwimou
  • zwisou
  • zwsiew
  • zwsiewale

  SOLUTION

Minimum Scan Engine: 9.700
FIRST VSAPI PATTERN FILE: 11.174.03
FIRST VSAPI PATTERN DATE: 26 Sep 2014
VSAPI OPR PATTERN File: 11.175.00
VSAPI OPR PATTERN Date: 26 Sep 2014

Step 1

Before doing any scans, Windows XP, Windows Vista, and Windows 7 users must disable System Restore to allow full scanning of their computers.

Step 2

Scan your computer with your Trend Micro product to delete files detected as PERL_SHELLBOT.WZ. If the detected files have already been cleaned, deleted, or quarantined by your Trend Micro product, no further step is required. You may opt to simply delete the quarantined files. Please check this Knowledge Base page for more information.


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