RANSOM_WALTRIX.Y

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.

This is the Trend Micro detection for files that exhibit certain behaviors.

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.

This malware arrives via the following means:

• delivered by exploit kits

Installation

This Trojan drops the following component file(s):

• {malware path}\explorer.exe - legitimate rundll32.exe
• %User Startup%\!{unique ID}{random character 1}.lnk - component that automatically opens the image ransom note upon system startup
• %User Startup%\!{unique ID}{random character 2}.lnk - component that automatically opens the HTML ransom note upon system startup
• %Start Menu%\Programs\!{unique ID}.html
• %Start Menu%\Programs\!{unique ID}.bmp
• %Start Menu%\Programs\!{unique ID}.txt
• %Desktop%\!{unique ID}.bmp - ransom image
• %Desktop%\!{unique ID}.html - ransom note
• %Desktop%\!{unique ID}.txt - ransom note
• {folders containing encrypted files}\!{unique ID}.html - ransom note
• {folders containing encrypted files}\!{unique ID}.txt - ransom note
• For Windows XP and below:
  • %All Users Profile%\Application Data\Z - deleted afterwards. This contains the installation date of the malware
  • %User Profile%\NetHood\!{unique ID}.html
  • %User Profile%\NetHood\!{unique ID}.bmp
  • %User Profile%\NetHood\!{unique ID}.txt
  • %All Users Profile%\Application Data\!unique ID}.cfg - deleted afterwards
  • %All Users Profile%\Application Data\!{unique ID}.bmp - lockscreen image
  • %All Users Profile%\Application Data\!{unique ID}.html - ransom note

    where {unique ID} contains 12 hexadecimal characters

• For Windows 7 and above:
  • %ProgramData%\Z - deleted afterwards. This contains the installation date of the malware
  • %Application Data%\Microsoft\Windows\Network Shortcuts\!Recovery_{unique ID}.html
  • %Application Data%\Microsoft\Windows\Network Shortcuts\!Recovery_{unique ID}.bmp
  • %Application Data%\Microsoft\Windows\Network Shortcuts\!Recovery_{unique ID}.txt
  • %ProgramData%\!{unique ID}.cfg - deleted afterwards
  • %ProgramData%\!{unique ID}.bmp - lockscreen image
  • %ProgramData%\!{unique ID}.html - ransom note

    where {unique ID} contains 12 hexadecimal characters

(Note: %User Startup% is the current user's Startup folder, which is usually C:\Documents and Settings\{user}\Start Menu\Programs\Startup on Windows 2000 and XP, and C:\Documents and Settings\{User name}\Start Menu\Programs\Startup on Windows Vista, 7, and 8.. %Start Menu% is the Start Menu folder, where it usually is C:\Documents and Settings\{user name}\Start Menu on Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\Users\{user name}\AppData\Roaming\Microsoft\Windows\Start Menu 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.. %User Profile% is the current user's profile folder, which is usually C:\Documents and Settings\{user name} on Windows 2000, XP, and Server 2003, or C:\Users\{user name} on Windows Vista and 7.. %Application Data% is the Application Data folder, where it usually is C:\Documents and Settings\{user name}\Application Data on Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\Users\{user name}\AppData\Roaming 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.)

It adds the following processes:

• {malware path}\explorer.exe {malware path and filename}.dll,XXS{number}S

  It copies the legitimate rundll32.exe as explorer.exe to the same directory of the ransomware.

Autostart Technique

This Trojan drops the following file(s) in the Windows User Startup folder to enable its automatic execution at every system startup:

• %User Startup%\!{unique ID}.lnk
  where {unique ID} contains 12 hexadecimal characters

(Note: %User Startup% is the current user's Startup folder, which is usually C:\Documents and Settings\{user}\Start Menu\Programs\Startup on Windows 2000 and XP, and C:\Documents and Settings\{User name}\Start Menu\Programs\Startup on Windows Vista, 7, and 8.)

Other System Modifications

This Trojan modifies the following file(s):

• It encrypts files and appends the extension .crypz

Process Termination

This Trojan terminates the following processes if found running in the affected system's memory:

• cmd.exe
• taskmgr.exe
• msconfig.exe
• WerFault.exe

Other Details

This Trojan encrypts files with the following extensions:

• .3DM
• .3DS
• .3G2
• .3GP
• .4DB
• .4DL
• .4MP
• .7Z
• .A3D
• .ABM
• .ABS
• .ABW
• .ACCDB
• .ACT
• .ADN
• .ADP
• .AES
• .AF2
• .AF3
• .AFT
• .AFX
• .AGIF
• .AGP
• .AHD
• .AI
• .AIC
• .AIF
• .AIM
• .ALBM
• .ALF
• .ANI
• .ANS
• .APD
• .APK
• .APM
• .APNG
• .APP
• .APS
• .APT
• .APX
• .ARC
• .ART
• .ARW
• .ASC
• .ASE
• .ASF
• .ASK
• .ASM
• .ASP
• .ASPX
• .ASW
• .ASX
• .ASY
• .ATY
• .AVI
• .AWDB
• .AWP
• .AWT
• .AWW
• .AZZ
• .BAD
• .BAY
• .BBS
• .BDB
• .BDP
• .BDR
• .BEAN
• .BIB
• .BM2
• .BMP
• .BMX
• .BNA
• .BND
• .BOC
• .BOK
• .BRD
• .BRK
• .BRN
• .BRT
• .BSS
• .BTD
• .BTI
• .BTR
• .BZ2
• .C
• .C2
• .C4
• .C4D
• .CAL
• .CALS
• .CAN
• .CD5
• .CDB
• .CDC
• .CDG
• .CDMM
• .CDMT
• .CDR
• .CDR3
• .CDR4
• .CDR6
• .CDT
• .CER
• .CF
• .CFG
• .CFM
• .CFU
• .CGI
• .CGM
• .CIMG
• .CIN
• .CIT
• .CKP
• .CLASS
• .CLKW
• .CMA
• .CMD
• .CMX
• .CNM
• .CNV
• .COLZ
• .CPC
• .CPD
• .CPG
• .CPP
• .CPS
• .CPT
• .CPX
• .CRD
• .CRT
• .CRWL
• .CRYPT
• .CS
• .CSR
• .CSS
• .CSV
• .CSY
• .CUE
• .CV5
• .CVG
• .CVI
• .CVS
• .CVX
• .CWT
• .CXF
• .CYI
• .DAD
• .DAF
• .DB
• .DB3
• .DBF
• .DBK
• .DBT
• .DBV
• .DBX
• .DCA
• .DCB
• .DCH
• .DCS
• .DCT
• .DCU
• .DCX
• .DDL
• .DDOC
• .DDS
• .DED
• .DF1
• .DG
• .DGN
• .DGS
• .DHS
• .DIB
• .DIF
• .DIP
• .DIZ
• .DJV
• .DJVU
• .DM3
• .DMI
• .DMO
• .DNC
• .DNE
• .DOC
• .DOCB
• .DOCM
• .DOCX
• .DOCZ
• .DOT
• .DOTM
• .DOTX
• .DP1
• .DPP
• .DPX
• .DQY
• .DRW
• .DRZ
• .DSK
• .DSN
• .DSV
• .DT
• .DT2
• .DTA
• .DTD
• .DTSX
• .DTW
• .DVI
• .DVL
• .DWG
• .DX
• .DXB
• .DXF
• .DXL
• .ECO
• .ECW
• .ECX
• .EDB
• .EFD
• .EGC
• .EIO
• .EIP
• .EIT
• .EMD
• .EMF
• .EML
• .EMLX
• .EP
• .EPF
• .EPP
• .EPS
• .EPSF
• .EQL
• .ERF
• .ERR
• .ETF
• .ETX
• .EUC
• .EXR
• .FAL
• .FAQ
• .FAX
• .FB2
• .FB3
• .FBL
• .FBX
• .FCD
• .FCF
• .FDB
• .FDF
• .FDR
• .FDS
• .FDT
• .FDX
• .FDXT
• .FES
• .FFT
• .FH10
• .FH11
• .FH3
• .FH4
• .FH5
• .FH6
• .FH7
• .FH8
• .FIC
• .FID
• .FIF
• .FIG
• .FIL
• .FL
• .FLA
• .FLI
• .FLR
• .FLV
• .FM5
• .FMV
• .FODT
• .FOL
• .FP3
• .FP4
• .FP5
• .FP7
• .FPOS
• .FPT
• .FPX
• .FRM
• .FRT
• .FT10
• .FT11
• .FT7
• .FT8
• .FT9
• .FTN
• .FWDN
• .FXC
• .FXG
• .FZB
• .FZV
• .GADGET
• .GBK
• .GBR
• .GCDP
• .GDB
• .GDOC
• .GED
• .GEM
• .GEO
• .GFB
• .GGR
• .GIF
• .GIH
• .GIM
• .GIO
• .GLOX
• .GPD
• .GPG
• .GPN
• .GPX
• .GRO
• .GROB
• .GRS
• .GSD
• .GTHR
• .GTP
• .GV
• .GWI
• .GZ
• .H
• .HBK
• .HDB
• .HDP
• .HDR
• .HHT
• .HIS
• .HPG
• .HPGL
• .HPI
• .HPL
• .HS
• .HTC
• .HTM
• .HTML
• .HWP
• .HZ
• .I3D
• .IB
• .IBD
• .IBOOKS
• .ICN
• .ICON
• .IDC
• .IDEA
• .IDX
• .IFF
• .IGT
• .IGX
• .IHX
• .IIL
• .IIQ
• .IMD
• .INDD
• .INFO
• .INK
• .IPF
• .IPX
• .ITDB
• .ITW
• .IWI
• .J2C
• .J2K
• .JAR
• .JAS
• .JAVA
• .JB2
• .JBMP
• .JBR
• .JFIF
• .JIA
• .JIS
• .JKS
• .JNG
• .JOE
• .JP1
• .JP2
• .JPE
• .JPEG
• .JPG
• .JPG2
• .JPS
• .JPX
• .JRTF
• .JS
• .JSP
• .JTX
• .JWL
• .JXR
• .KDB
• .KDBX
• .KDC
• .KDI
• .KDK
• .KES
• .KEY
• .KIC
• .KLG
• .KML
• .KMZ
• .KNT
• .KON
• .KPG
• .KWD
• .LAY
• .LAY6
• .LBM
• .LBT
• .LDF
• .LGC
• .LIS
• .LIT
• .LJP
• .LMK
• .LNT
• .LP2
• .LRC
• .LST
• .LTR
• .LTX
• .LUA
• .LUE
• .LUF
• .LWO
• .LWP
• .LWS
• .LYT
• .LYXM
• .M3D
• .M3U
• .M4A
• .M4V
• .MA
• .MAC
• .MAN
• .MAP
• .MAQ
• .MAT
• .MAX
• .MB
• .MBM
• .MBOX
• .MDB
• .MDF
• .MDN
• .MDT
• .ME
• .MEF
• .MELL
• .MFD
• .MFT
• .MGCB
• .MGMT
• .MGMX
• .MID
• .MIN
• .MKV
• .MMAT
• .MML
• .MNG
• .MNR
• .MNT
• .MOBI
• .MOS
• .MOV
• .MP3
• .MP4
• .MPA
• .MPF
• .MPG
• .MPO
• .MRG
• .MRXS
• .MS11
• .MSG
• .MSI
• .MT9
• .MUD
• .MWB
• .MWP
• .MXL
• .MYD
• .MYI
• .MYL
• .NCR
• .NCT
• .NDF
• .NEF
• .NFO
• .NJX
• .NLM
• .NOTE
• .NOW
• .NRW
• .NS2
• .NS3
• .NS4
• .NSF
• .NV2
• .NYF
• .NZB
• .OBJ
• .OC3
• .OC4
• .OC5
• .OCE
• .OCI
• .OCR
• .ODB
• .ODG
• .ODM
• .ODO
• .ODP
• .ODS
• .ODT
• .OFL
• .OFT
• .OMF
• .OPLC
• .OQY
• .ORA
• .ORF
• .ORT
• .ORX
• .OTA
• .OTG
• .OTI
• .OTP
• .OTS
• .OTT
• .OVP
• .OVR
• .OWC
• .OWG
• .OYX
• .OZB
• .OZJ
• .OZT
• .P12
• .P7S
• .P96
• .P97
• .PAGES
• .PAL
• .PAN
• .PANO
• .PAP
• .PAQ
• .PAS
• .PB
• .PBM
• .PC1
• .PC2
• .PC3
• .PCD
• .PCS
• .PCT
• .PCX
• .PDB
• .PDD
• .PDF
• .PDM
• .PDN
• .PDS
• .PDT
• .PE4
• .PEF
• .PEM
• .PFF
• .PFI
• .PFS
• .PFV
• .PFX
• .PGF
• .PGM
• .PHM
• .PHP
• .PI
• .PI2
• .PI3
• .PIC
• .PICT
• .PIF
• .PIX
• .PJPG
• .PJT
• .PL
• .PLTE
• .PLUGIN
• .PM
• .PMG
• .PNG
• .PNI
• .PNM
• .PNTG
• .PNZ
• .POP
• .POT
• .POTM
• .POTX
• .PP4
• .PP5
• .PPAM
• .PPM
• .PPS
• .PPSM
• .PPSX
• .PPT
• .PPTM
• .PPTX
• .PPTX.20
• .PRF
• .PRIV
• .PRIVATE
• .PRT
• .PRW
• .PS
• .PSDE
• .PSDX
• .PSE
• .PSI
• .PSID
• .PSP
• .PSPIMAGE
• .PSW
• .PTG
• .PTH
• .PTX
• .PU
• .PVJ
• .PVM
• .PVR
• .PWA
• .PWI
• .PWR
• .PXR
• .PY
• .PZ3
• .PZA
• .PZP
• .PZS
• .QCOW2
• .QDL
• .QMG
• .QPX
• .QRY
• .QVD
• .RA
• .RAD
• .RAR
• .RAS
• .RAW
• .RCTD
• .RCU
• .RDB
• .RDDS
• .RDL
• .RFT
• .RGB
• .RGF
• .RIB
• .RIC
• .RIFF
• .RIS
• .RIX
• .RLE
• .RLI
• .RM
• .RNG
• .RPD
• .RPF
• .RPT
• .RRI
• .RSB
• .RSD
• .RSR
• .RSS
• .RST
• .RT
• .RTD
• .RTF
• .RTX
• .RUN
• .RW2
• .RWL
• .RZK
• .RZN
• .S2MV
• .S3M
• .SAF
• .SAI
• .SAM
• .SAVE
• .SBF
• .SCAD
• .SCC
• .SCH
• .SCI
• .SCM
• .SCT
• .SCV
• .SCW
• .SDB
• .SDF
• .SDM
• .SDOC
• .SDW
• .SEP
• .SFC
• .SFW
• .SGM
• .SH
• .SIG
• .SITX
• .SK1
• .SK2
• .SKM
• .SLA
• .SLD
• .SLDX
• .SLK
• .SLN
• .SLS
• .SMF
• .SMIL
• .SMS
• .SOB
• .SPA
• .SPE
• .SPH
• .SPJ
• .SPP
• .SPQ
• .SPR
• .SQB
• .SQL
• .SQLITE3
• .SQLITEDB
• .SR2
• .SRT
• .SRW
• .SSA
• .SSK
• .ST
• .STC
• .STD
• .STE
• .STI
• .STM
• .STN
• .STP
• .STR
• .STW
• .STY
• .SUB
• .SUMO
• .SVA
• .SVF
• .SVG
• .SVGZ
• .SWF
• .SXC
• .SXD
• .SXG
• .SXI
• .SXM
• .SXW
• .T2B
• .TAB
• .TAR
• .TB0
• .TBK
• .TBN
• .TCX
• .TDF
• .TDT
• .TE
• .TEX
• .TEXT
• .TF
• .TFC
• .TG4
• .TGA
• .TGZ
• .THM
• .THP
• .TIF
• .TIFF
• .TJP
• .TLB
• .TLC
• .TM
• .TM2
• .TMD
• .TMP
• .TMV
• .TMX
• .TN
• .TNE
• .TPC
• .TPI
• .TRM
• .TVJ
• .TXT
• .U3D
• .U3I
• .UDB
• .UFO
• .UFR
• .UGA
• .UNX
• .UOF
• .UOP
• .UOT
• .UPD
• .USR
• .UTF8
• .UTXT
• .V12
• .VB
• .VBR
• .VBS
• .VCF
• .VCT
• .VCXPROJ
• .VDA
• .VDB
• .VDI
• .VEC
• .VFF
• .VMDK
• .VML
• .VMX
• .VNT
• .VOB
• .VPD
• .VPE
• .VRML
• .VRP
• .VSD
• .VSDM
• .VSDX
• .VSM
• .VST
• .VSTX
• .VUE
• .VW
• .WAV
• .WB1
• .WBC
• .WBD
• .WBK
• .WBM
• .WBMP
• .WBZ
• .WCF
• .WDB
• .WDP
• .WEBP
• .WGZ
• .WIRE
• .WKS
• .WMA
• .WMDB
• .WMF
• .WMV
• .WN
• .WP
• .WP4
• .WP5
• .WP6
• .WP7
• .WPA
• .WPD
• .WPE
• .WPG
• .WPL
• .WPS
• .WPT
• .WPW
• .WRI
• .WSC
• .WSD
• .WSF
• .WSH
• .WTX
• .WVL
• .X3D
• .X3F
• .XAR
• .XCODEPROJ
• .XDB
• .XDL
• .XHTM
• .XHTML
• .XLC
• .XLD
• .XLF
• .XLGC
• .XLM
• .XLR
• .XLS
• .XLSB
• .XLSM
• .XLSX
• .XLT
• .XLTM
• .XLTX
• .XLW
• .XML
• .XPM
• .XPS
• .XWP
• .XY3
• .XYP
• .XYW
• .YAL
• .YBK
• .YML
• .YSP
• .YUV
• .Z3D
• .ZABW
• .ZDB
• .ZDC
• .ZIF
• .ZIP
• .ZIPX
• .ZW

This is the Trend Micro detection for:

• CryptXXX version 3.201

It does the following:

• It locks the screen after file encryption routine
• It avoids to encrypt the following files/folders:
  • \WINDOWS\
  • \WINNT
  • \RECYCLER\
  • \SYSTEM~1\
  • \BOOT\
  • \RECOVERY\
  • \$RECYCLE.BIN\
  • \PERFLOGS\
  • \EFI\
  • \CONFIG.MSI\
  • \PROGRA~1\
  • \PROGRA~2\
  • \GOOGLE\
  • \TEMP\
  • \F4BC~1\
  • \ALLUSE~1\
  • \PROGRA~1\
  • \PROGRA~2\
  • \APPDATA\
  • \PROGRA~3\
  • \PUBLIC\
  • AUTOEXEC.BAT
  • THUMBS.DB
  • \APPLIC~1\
  • \COOKIES\
  • \LOCALS~1\
  • \TEMPLA~1\
• It deletes shadow copies using vssadmin.exe
• It deletes itself as well as its LNK startup after the user chooses to reboot the system
• It reports infection status and unique ID to {BLOCKED}.{BLOCKED}.194.116:443 and {BLOCKED}.{BLOCKED}.236.7:443.

NOTES:

This ransomware locks the screen and displays the following image:

The following is the content of the ransom note !{unique ID}.html: