TROJ_NYMAIM.SAJ
Trojan.Win32.Nymaim.AY (Baidu-International); Win32/TrojanDownloader.Nymaim.AY (ESET-NOD32); Ransom:Win32/Nymaim.F (Microsoft); Trojan.Win32.Yakes.lazm (Kaspersky); W32/Generic.AC.2045128 (Fortinet)
Windows
Threat Type: Trojan
Destructiveness: No
Encrypted:
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.
However, as of this writing, the said sites are inaccessible.
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 drops the following files:
- %Start Menu%\Programs\Startupx\system.pif
- %Windows%\{random filename 1}.{random extension}
- %Windows%\{random filename 2}.{random extension}
(Note: %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.. %Windows% is the Windows folder, where it usually is C:\Windows on all Windows operating system versions.)
Other System Modifications
This Trojan adds the following registry keys:
HKEY_CURRENT_USER\Software\{malware filename}
HKEY_CURRENT_USER\Software\{malware filename}\
Recent File List
HKEY_CURRENT_USER\Software\{malware filename}\
Settings
Other Details
This Trojan connects to the following possibly malicious URL:
- http://{BLOCKED}d.ru/10573/w6zi7nh/index.php
However, as of this writing, the said sites are inaccessible.
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
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.
- In HKEY_CURRENT_USER\Software
- {malware filename}
- {malware filename}
Step 4
Search and delete this file
- %Start Menu%\Programs\Startupx\system.pif
- %Windows%\{random filename 1}.{random extension}
- %Windows%\{random filename 2}.{random extension}
Step 5
Scan your computer with your Trend Micro product to delete files detected as TROJ_NYMAIM.SAJ. 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.
Did this description help? Tell us how we did.