RANSOM_CRYPZXAS.B
a variant of MSIL/Filecoder.CA (ESET);
Windows
Threat Type: Trojan
Destructiveness: No
Encrypted: Yes
In the wild: Yes
OVERVIEW
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.
TECHNICAL DETAILS
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 adds the following processes:
- excel.exe
Other Details
This Trojan encrypts files with the following extensions:
- .1cd
- .7z
- .accdb
- .ai
- .arj
- .arw
- .bmp
- .cd
- .cdr
- .cr2
- .db
- .dbf
- .doc
- .docx
- .epf
- .jpeg
- .jpg
- .ldf
- .max
- .md
- .mdb
- .mdf
- .nef
- .nrf
- .odb
- .odg
- .ods
- .odt
- .orf
- .png
- .ppt
- .pptx
- .psd
- .rar
- .rtf
- .sr2
- .srf
- .tar
- .tif
- .xls
- .xlsx
- .zip
It renames encrypted files using the following names:
- {original filename and file extension}.blocked
NOTES:
This ransomware drops the following files whenever it is able to successfully encrypt files:
- keyvalue.bin
- !!!!!!!! c3 8a c3 a0 c3 aa c3 a2 c3 ae c3 b1 c3 b1 c3 b2 c3 a0 c3 ad c3 ae c3 a2 c3 a8 c3 b2 c3 bc c3 b4 c3 a0 c3 a9 c3 ab c3 bb!!!!!!!.txt
It avoids encrypting files in the following folders:
- %System%
- %Program Files%
- System Volume Information
- $RECYCLE.BIN
- RECYCLER
It executes the following to delete shadow copies:
vssadmin.exe Delete Shadows /All /Quiet
It encrypts files in fixed and network drives. It performs net view and finds диск which is Russian for Disk. It then tries to encrypt on the shared network disk resources it finds.
SOLUTION
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
Search and delete these files
- keyvalue.bin
- !!!!!!!!Êàê âîññòàíîâèòü ôàéëû!!!!!!!.txt
Step 4
Scan your computer with your Trend Micro product to delete files detected as RANSOM_CRYPZXAS.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 5
Restore encrypted files from backup.
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