RANSOM_NANOLOCKER.B

 Analysis by: Christian Noel Olalia

 ALIASES:

Ransom.NanoLocker (NORTON); Gen:Variant.Razy.90557 (BITDEFENDER); Ransomware-FCO!FCE023BE1FB2 (NAI)

 PLATFORM:

Windows

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

  • Threat Type: Ransomware

  • Destructiveness: No

  • Encrypted: No

  • In the wild: Yes

  OVERVIEW

Infection Channel:

Downloaded from the Internet

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

It encrypts files with specific file extensions. It encrypts files found in specific folders. It drops files as ransom note.

  TECHNICAL DETAILS

File Size:

201,216 bytes

File Type:

EXE

Memory Resident:

Yes

Initial Samples Received Date:

18 Jun 2017

Payload:

Displays message/message boxes, Encrypts files

Arrival Details

This Ransomware 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 Ransomware drops a copy of itself in the following folders using different file names:

  • %AppDataLocal%\lansrv.exe

(Note: %AppDataLocal% is the Application Data folder found in Local Settings, where it is usually C:\Documents and Settings\{user name}\Local Settings\Application Data on Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\Users\{user name}\AppData\Local on Windows Vista (32- and 64-bit), Windows 7 (32- and 64-bit), Windows 8 (32- and 64-bit), Windows 8.1 (32- and 64-bit), Windows Server 2008, and Windows Server 2012.)

Autostart Technique

This Ransomware adds the following registry entries to enable its automatic execution at every system startup:

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
LanmanServer = %AppDataLocal%\lansrv.exe

Other Details

This Ransomware drops the following file(s)/component(s):

  • %AppDataLocal%\lansrv.ini - contains list of encrypted files
  • %Desktop%\Decryptor.lnk - shortcut to malware copy

(Note: %AppDataLocal% is the Application Data folder found in Local Settings, where it is usually C:\Documents and Settings\{user name}\Local Settings\Application Data on Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\Users\{user name}\AppData\Local on Windows Vista (32- and 64-bit), Windows 7 (32- and 64-bit), Windows 8 (32- and 64-bit), Windows 8.1 (32- and 64-bit), Windows Server 2008, and Windows Server 2012.. %Desktop% is the desktop folder, where it usually is C:\Documents and Settings\{user name}\Desktop in Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\Users\{user name}\Desktop in Windows Vista (32- and 64-bit), Windows 7 (32- and 64-bit), Windows 8 (32- and 64-bit), Windows 8.1 (32- and 64-bit), Windows Server 2008, and Windows Server 2012.)

It does the following:

  • After encryption, the shortcut to malware copy is executed and displays the following:

Ransomware Routine

This Ransomware encrypts files with the following extensions:

  • .jpg
  • .jpeg
  • .tif
  • .bmp
  • .max
  • .accdb
  • .dbf
  • .mdb
  • .pdb
  • .sql
  • .sav
  • .spv
  • .grle
  • .mlx
  • .game
  • .slot
  • .dwg
  • .dxf
  • .cpp
  • .php
  • .asp
  • .java
  • .jar
  • .class
  • .aaf
  • .aep
  • .aepx
  • .plb
  • .prel
  • .prproj
  • .aet
  • .ppj
  • .psd
  • .indd
  • .indl
  • .indt
  • .indb
  • .inx
  • .idml
  • .pmd
  • .xqx
  • .eps
  • .svg
  • .swf
  • .fla
  • .doc
  • .dot
  • .docx
  • .docm
  • .dotx
  • .dotm
  • .docb
  • .rtf
  • .wpd
  • .wps
  • .msg
  • .pdf
  • .xls
  • .xlt
  • .xlm
  • .xlsx
  • .xlsm
  • .xltx
  • .xltm
  • .xlsb
  • .xla
  • .xlam
  • .xll
  • .xlw
  • .ppt
  • .pot
  • .pps
  • .pptx
  • .pptm
  • .potx
  • .potm
  • .ppam
  • .ppsx
  • .ppsm
  • .sldx
  • .sldm
  • .wav
  • .aif
  • .iff
  • .mid
  • .mpa
  • .wma
  • .avi
  • .mov
  • .mpeg
  • .asf
  • .asx
  • .flv
  • .mpg
  • .wmv
  • .vob
  • .csv
  • .efx
  • .sdf
  • .vcf
  • .xml
  • .crt
  • .pem
  • .cer
  • .pfx
  • .odt
  • .ods
  • .odp
  • .odm
  • .odb
  • .odc
  • .xlk
  • .dxg
  • .pst
  • .mdf
  • .cdr
  • .arw
  • .dng
  • .rar
  • .zip
  • .srf
  • .bay
  • .crw
  • .dcr
  • .kdc
  • .erf
  • .mef
  • .mrw
  • .nef
  • .nrw
  • .orf
  • .raf
  • .raw
  • .rwl
  • .ptx
  • .pef
  • .srw
  • .der

It encrypts files found in the following folders:

  • {Drive Letter}:\

It drops the following file(s) as ransom note:

  • %Desktop%\ATTENTION.RTF

  SOLUTION

Minimum Scan Engine:

9.850

FIRST VSAPI PATTERN FILE:

13.480.08

FIRST VSAPI PATTERN DATE:

19 Jun 2017

VSAPI OPR PATTERN File:

13.481.00

VSAPI OPR PATTERN Date:

20 Jun 2017

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

Identify and terminate files detected as RANSOM_NANOLOCKER.B

[ Learn More ]
  1. Windows Task Manager may not display all running processes. In this case, please use a third-party process viewer, preferably Process Explorer, to terminate the malware/grayware/spyware file. You may download the said tool here.
  2. If the detected file is displayed in either Windows Task Manager or Process Explorer but you cannot delete it, restart your computer in safe mode. To do this, refer to this link for the complete steps.
  3. If the detected file is not displayed in either Windows Task Manager or Process Explorer, continue doing the next steps.

Step 4

Restart in Safe Mode

[ Learn More ]

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_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run
    • LanmanServer = %AppDataLocal%\lansrv.exe

Step 6

Search and delete these files

[ Learn More ]
There may be some files that are hidden. Please make sure you check the Search Hidden Files and Folders checkbox in the "More advanced options" option to include all hidden files and folders in the search result.  
  • %AppDataLocal%\lansrv.exe
  • %AppDataLocal%\lansrv.ini
  • %Desktop%\ATTENTION.RTF
  • %Desktop%\Decryptor.lnk

Step 7

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

Step 8

Restore encrypted files from backup.


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