BKDR_FYNLOSKI.YYSZN
Packed-RW!54B9EEC24D58 (McAfee), W32/Kryptik.FWYQ!tr (Fortinet)
Windows
![](/vinfo/imgFiles/legend.jpg)
Threat Type: Backdoor
Destructiveness: No
Encrypted:
In the wild: Yes
OVERVIEW
This Backdoor 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
1334322 bytes
EXE
Yes
Arrival Details
This Backdoor 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 Backdoor drops the following copies of itself into the affected system:
- %System Root%\BigView\BigView.exe
(Note: %System Root% is the Windows root folder, where it usually is C:\ on all Windows operating system versions.)
It creates the following folders with attributes set to System and Hidden to prevent users from discovering and removing its components:
- %System Root%\BigView
(Note: %System Root% is the Windows root folder, where it usually is C:\ on all Windows operating system versions.)
Autostart Technique
This Backdoor adds the following registry entries to enable its automatic execution at every system startup:
HKCU\Software\Microsoft\
Windows\CurrentVersion\Run
BigView\ = %System Root%\BigView\BigView.exe
Other System Modifications
This Backdoor adds the following registry keys:
HKEY_CURRENT_USER\Software\DC3_FEXEC
SOLUTION
9.850
13.712.05
11 Oct 2017
13.713.00
12 Oct 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 BKDR_FYNLOSKI.YYSZN
- 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.
- 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.
- If the detected file is not displayed in either Windows Task Manager or Process Explorer, continue doing the next steps.
Step 4
Delete this registry value
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
- BigView\ = "%System Root%\BigView\BigView.exe"
- BigView\ = "%System Root%\BigView\BigView.exe"
Step 5
Delete this registry key
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.
- HKEY_CURRENT_USER\Software\DC3_FEXEC
Step 6
Search and delete this folder
- %System Root%\BigView
Step 7
Scan your computer with your Trend Micro product to delete files detected as BKDR_FYNLOSKI.YYSZN. 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:
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