Ransom.Win32.CONTI.YAAI-A
HEUR:Trojan-Ransom.Win32.Gen.gen (KASPERSKY)
Windows

Threat Type: Ransomware
Destructiveness: No
Encrypted: Yes
In the wild: Yes
OVERVIEW
Dropped by other malware, 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 drops files as ransom note.
TECHNICAL DETAILS
519,680 bytes
EXE
No
18 Sep 2020
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 the following copies of itself into the affected system and executes them:
- %AppDataLocal%\Microsoft\Windows\Temporary Internet Files\պԴպեԵղԸԴԶԽՈԻՖՑԾիքցիֆուպԼՆԹԿԱփԾոքգԽղԻՖՑԾՊՃճվԷՉՃԲէւպհվՒՉլնբԷՉԿԲրջպճ\պԴպեԵղԸԴԶԽՈԻՖՑԾիքցիֆուպԼՆԹԿԱփԾոքգԽղԻՖՑԾՊՃճվԷՉՃԲէւպհվՒՉլնբԷՉԿԲրջպճ.exe (if MsMpEng.exe runs on the system)
(Note: %AppDataLocal% is the Local Application Data folder, which is usually C:\Documents and Settings\{user name}\Local Settings\Application Data on Windows 2000(32-bit), XP, and Server 2003(32-bit), or C:\Users\{user name}\AppData\Local on Windows Vista, 7, 8, 8.1, 2008(64-bit), 2012(64-bit) and 10(64-bit).)
It drops the following files:
- %System Root%\CONTI_LOG.txt (if parameter has -log)
(Note: %System Root% is the Windows root folder, where it usually is C:\ on all Windows operating system versions.)
It adds the following processes:
- %AppDataLocal%\Microsoft\Windows\Temporary Internet Files\պԴպեԵղԸԴԶԽՈԻՖՑԾիքցիֆուպԼՆԹԿԱփԾոքգԽղԻՖՑԾՊՃճվԷՉՃԲէւպհվՒՉլնբԷՉԿԲրջպճ\պԴպեԵղԸԴԶԽՈԻՖՑԾիքցիֆուպԼՆԹԿԱփԾոքգԽղԻՖՑԾՊՃճվԷՉՃԲէւպհվՒՉլնբԷՉԿԲրջպճ.exe (if MsMpEng.exe runs on the system)
(Note: %AppDataLocal% is the Local Application Data folder, which is usually C:\Documents and Settings\{user name}\Local Settings\Application Data on Windows 2000(32-bit), XP, and Server 2003(32-bit), or C:\Users\{user name}\AppData\Local on Windows Vista, 7, 8, 8.1, 2008(64-bit), 2012(64-bit) and 10(64-bit).)
It adds the following mutexes to ensure that only one of its copies runs at any one time:
- {Random characters}
Other Details
This Ransomware accepts the following parameters:
- -h - Specify file for IP list to focus on network shares
- -log - Log output to %System Root%\CONTI_LOG.txt
(Note: %System Root% is the Windows root folder, where it usually is C:\ on all Windows operating system versions.)
Ransomware Routine
This Ransomware appends the following extension to the file name of the encrypted files:
- .EBEAR
It drops the following file(s) as ransom note:
- {Encrypted folder}\R3ADM3.txt
SOLUTION
9.800
16.240.07
21 Sep 2020
16.241.00
22 Sep 2020
Step 1
Trend Micro Predictive Machine Learning detects and blocks malware at the first sign of its existence, before it executes on your system. When enabled, your Trend Micro product detects this malware under the following machine learning name:
- Troj.Win32.TRX.XXPE50FFF037
Step 2
Before doing any scans, Windows 7, Windows 8, Windows 8.1, and Windows 10 users must disable System Restore to allow full scanning of their computers.
Step 3
Search and delete these files
- %AppDataLocal%\Microsoft\Windows\Temporary Internet Files\պԴպեԵղԸԴԶԽՈԻՖՑԾիքցիֆուպԼՆԹԿԱփԾոքգԽղԻՖՑԾՊՃճվԷՉՃԲէւպհվՒՉլնբԷՉԿԲրջպճ\պԴպեԵղԸԴԶԽՈԻՖՑԾիքցիֆուպԼՆԹԿԱփԾոքգԽղԻՖՑԾՊՃճվԷՉՃԲէւպհվՒՉլնբԷՉԿԲրջպճ.exe
- %System Root%\CONTI_LOG.txt
- {Encrypted folder}\R3ADM3.txt
Step 4
Scan your computer with your Trend Micro product to delete files detected as Ransom.Win32.CONTI.YAAI-A. 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 the following Trend Micro Support pages for more information:
Step 5
Restore encrypted files from backup.
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