TROJ_BAYROB.VTL

 Analysis by: Janus Agcaoili

 ALIASES:

TrojanSpy:Win32/Nivdort.DI (Microsoft), Mal/Bayrob-C (Sophos), Trojan.Win32.Bayrob (Ikarus), W32/Bayrob.AT!tr (Fortinet)

 PLATFORM:

Windows

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

  • Threat Type: Trojan

  • Destructiveness: No

  • Encrypted: Yes

  • In the wild: Yes

  OVERVIEW

Infection Channel:

Downloaded from the Internet, Dropped by other malware


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

It does not have any propagation routine.

It does not have any backdoor routine.

As of this writing, the said sites are inaccessible.

It does not have any information-stealing capability.

  TECHNICAL DETAILS

File Size:

385,536 bytes

File Type:

EXE

Memory Resident:

Yes

Initial Samples Received Date:

20 Jan 2016

Payload:

Connects to URLs/IPs, Displays message/message boxes

Arrival Details

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

Installation

This Trojan drops the following copies of itself into the affected system and executes them:

  • %System Root%\{random string1}\{random string2}.exe
  • %System Root%\{random string1}\{random string3}.exe
  • %System Root%\{random string1}\{random string4}.exe <- Deleted afterwards

(Note: %System Root% is the Windows root folder, where it usually is C:\ on all Windows operating system versions.)

It drops the following files:

  • %System Root%\{random string1}\{random string5}
  • %Windows%\{random string1\{random string5}
  • %System Root%\{random string1}\{random string6}
  • %System Root%\{random string1}\{random string7}

(Note: %System Root% is the Windows root folder, where it usually is C:\ on all Windows operating system versions.. %Windows% is the Windows folder, where it usually is C:\Windows on all Windows operating system versions.)

It creates the following folders:

  • %System Root%\{random string1}
  • %Windows%\{random string1}

(Note: %System Root% is the Windows root folder, where it usually is C:\ on all Windows operating system versions.. %Windows% is the Windows folder, where it usually is C:\Windows on all Windows operating system versions.)

It displays the following fake error messages:


Autostart Technique

This Trojan adds and runs the following services:

  • Service Name: Upgrade Parental Adaptive Registrar
    Display Name: Upgrade Parental Adaptive Registrar
    Start Type: SERVICE_AUTO_START
    Binary Pathname: %System Root%\{random string1}\{random string2}.exe

(Note: %System Root% is the Windows root folder, where it usually is C:\ on all Windows operating system versions.)

Other System Modifications

This Trojan modifies the following registry entries:

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
services\TrustedInstaller
Start = "2"

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
services\TrustedInstaller
Start = "3"

Propagation

This Trojan does not have any propagation routine.

Backdoor Routine

This Trojan does not have any backdoor routine.

Download Routine

This Trojan accesses the following websites to download files:

  • http://{hostname}.net/index.php

As of this writing, the said sites are inaccessible.

Information Theft

This Trojan does not have any information-stealing capability.

NOTES:

The {hostname} is generated through concatenating two strings from the following list:

  • journey
  • destroy
  • against
  • night
  • within
  • effort
  • street
  • better
  • husband
  • little
  • doubt
  • decide
  • suffer
  • through
  • trade
  • gather
  • ridden
  • chair
  • large
  • record
  • forget
  • would
  • flier
  • quiet
  • belong
  • those
  • captain
  • electric
  • increase
  • remember
  • bread
  • season
  • degree
  • answer
  • think
  • chief
  • order
  • leader
  • rather
  • strange
  • forward
  • glass
  • present
  • college
  • require
  • heaven
  • morning
  • history
  • difficult
  • pleasant
  • often
  • middle
  • heavy
  • various
  • amount
  • thick
  • heard
  • necessary
  • alone
  • twelve
  • gentle
  • return
  • weather
  • class
  • movement
  • building
  • fresh
  • gentleman
  • fellow
  • broken
  • summer
  • thought
  • outside
  • evening
  • experience
  • already
  • double
  • result
  • crowd
  • water
  • store
  • doctor
  • follow
  • begin
  • prepare
  • strength
  • woman
  • party
  • might
  • pretty
  • member
  • known
  • desire
  • still
  • smoke
  • fight
  • expect
  • person
  • severa
  • simple
  • figure
  • picture
  • winter
  • finish
  • because
  • machine
  • laugh
  • mother
  • though
  • cigarette
  • subject
  • leave
  • sudden
  • whether
  • mountain
  • perhaps
  • children
  • either
  • sweet
  • several
  • foreign
  • right
  • possible
  • window
  • family
  • english
  • probably
  • material
  • shore
  • welcome
  • dollar
  • proud
  • should
  • industry
  • opinion
  • contain
  • character
  • nature
  • board
  • enough
  • supply
  • settle
  • office
  • device
  • beyond
  • silver
  • forever
  • valley
  • matter
  • school
  • together
  • question
  • flower
  • bring
  • special
  • demand
  • father
  • hunger
  • built
  • storm
  • written
  • around
  • realize
  • complete
  • short
  • became
  • promise
  • basket
  • ladder
  • needle
  • enter
  • govern
  • distance
  • language
  • arrive
  • before
  • being
  • sister
  • bottom
  • labor
  • spent
  • while
  • control
  • therefore
  • minute
  • listen
  • corner
  • shout
  • apple
  • training
  • carry
  • thrown
  • length
  • laughter
  • indeed
  • consider
  • almost
  • attempt
  • orderly
  • neighbor
  • clear
  • smell
  • include
  • safety
  • chance
  • market
  • twenty
  • beauty
  • clean
  • ready
  • course
  • people
  • understand
  • succeed
  • behind
  • produce
  • stream
  • nation
  • bottle
  • please
  • dried
  • round
  • angry
  • likely
  • notice
  • fancy
  • during
  • friend
  • reason
  • square
  • value
  • spread
  • general
  • early
  • north
  • future
  • meeting
  • report
  • understood
  • garden
  • paint
  • brown
  • women
  • daughter
  • broad
  • between
  • butter
  • student
  • nothing
  • soldier
  • divide
  • condition
  • fifteen
  • glossary
  • article
  • worth
  • except
  • further
  • bicycle
  • become
  • strong
  • found
  • president
  • success
  • wagon
  • until
  • kitchen
  • shoulder
  • continue
  • airplane
  • wonder
  • guard
  • advance
  • station
  • goodbye
  • object
  • measure
  • choose
  • afraid
  • period
  • escape
  • space
  • problem
  • yellow
  • wheat
  • single
  • always
  • difference
  • bridge
  • cover
  • whose
  • company
  • trouble
  • spring
  • caught
  • banker
  • without
  • above
  • probable
  • finger
  • master
  • straight
  • discover
  • fence
  • stranger
  • third
  • fortieth
  • childhood
  • dinner
  • although
  • circle
  • however
  • animal
  • travel
  • modern
  • close
  • anger
  • charge
  • forest
  • every
  • branch
  • separate
  • receive
  • clothes
  • borrow
  • toward
  • electricity
  • million
  • honor
  • catch
  • system
  • public
  • number
  • heart
  • strike
  • mayor
  • manner
  • century
  • business
  • power
  • mister
  • method
  • service
  • direct
  • instead
  • surprise
  • bright
  • letter
  • nearly
  • speak
  • shake
  • write
  • believe
  • health
  • quarter
  • distant
  • train
  • pleasure
  • delight
  • white
  • neither
  • eearly
  • trust
  • dress
  • position
  • perfect
  • partial
  • battle
  • another
  • famous
  • appear
  • country
  • suppose
  • action
  • river
  • brought
  • explain
  • beside
  • inside
  • different
  • happen
  • niece
  • share
  • oclock

  SOLUTION

Minimum Scan Engine:

9.800

FIRST VSAPI PATTERN FILE:

12.284.05

FIRST VSAPI PATTERN DATE:

20 Jan 2016

VSAPI OPR PATTERN File:

12.285.00

VSAPI OPR PATTERN Date:

21 Jan 2016

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

Note that not all files, folders, and registry keys and entries are installed on your computer during this malware's/spyware's/grayware's execution. This may be due to incomplete installation or other operating system conditions. If you do not find the same files/folders/registry information, please proceed to the next step.

Step 3

Restart in Safe Mode

[ Learn More ]

Step 4

Disable this malware service

[ Learn More ]
  •  Upgrade Parental Adaptive Registrar

Step 5

Delete this registry value

[ Learn More ]

Important: Editing the Windows Registry incorrectly can lead to irreversible system malfunction. Please do this step only if you know how or you can ask assistance from your system administrator. Else, check this Microsoft article first before modifying your computer's registry.

  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\services\TrustedInstaller
    • Start = "2"
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\services\TrustedInstaller
    • Start = "3"

Step 6

Search and delete these folders

[ Learn More ]
Please make sure you check the Search Hidden Files and Folders checkbox in the More advanced options option to include all hidden folders in the search result.
  • %System Root%\{random string1}
  • %Windows%\{random string1}

Step 7

Restart in normal mode and scan your computer with your Trend Micro product for files detected as TROJ_BAYROB.VTL. 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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