Worm.Win32.NITOL.AJP
Trojan.Win32.MicroFake.ba (Kaspersky); DDoS:Win32/Nitol (Microsoft)
Windows

Threat Type: Worm
Destructiveness: No
Encrypted: No
In the wild: Yes
OVERVIEW
Dropped by other malware, Downloaded from the Internet
This Worm 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
46,592 bytes
EXE
No
19 Jan 2011
Drops files
Arrival Details
This Worm 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 Worm drops the following copies of itself into the affected system and executes them:
- %User Temp%\IRAR{random characters}.tmp\lpk.dll
(Note: %User Temp% is the current user's Temp folder, which is usually C:\Documents and Settings\{user name}\Local Settings\Temp on Windows 2000, XP, and Server 2003, or C:\Users\{user name}\AppData\Local\Temp on Windows Vista, 7, and 8.)
It drops and executes the following files:
- %User Temp%\hrl{random}.tmp <- detected as WORM_MICROFAKE.U
- %System%\{random}.exe <- detected as WORM_MICROFAKE.U
It creates the following folders:
- %User Temp%\IRAR{random characters}.tmp
(Note: %User Temp% is the current user's Temp folder, which is usually C:\Documents and Settings\{user name}\Local Settings\Temp on Windows 2000, XP, and Server 2003, or C:\Users\{user name}\AppData\Local\Temp on Windows Vista, 7, and 8.)
It adds the following mutexes to ensure that only one of its copies runs at any one time:
- Distribumkq
Other System Modifications
This Worm deletes the following folders:
- %User Temp%\IRAR{random characters}.tmp
(Note: %User Temp% is the current user's Temp folder, which is usually C:\Documents and Settings\{user name}\Local Settings\Temp on Windows 2000, XP, and Server 2003, or C:\Users\{user name}\AppData\Local\Temp on Windows Vista, 7, and 8.)
Other Details
This Worm does the following:
- Drops the following files in All drives and its sub-folders containing an EXE:
- {All Drives}\lpk.dll
- {All Drives}\{Sub-Folder}\lpk.dll
- Adds the following processes to add itself inside an archive(.zip or .rar):
- cmd /c {directory of WinRAR} vb "{All Drives}\{Directory of archive}\{Name of archive(.zip or .rar)}" lpk.dll | find /i "lpk.dll"
- {directory of WinRAR} x "{All Drives}\{Directory of archive}\{Name of archive(.zip or .rar)}" *.exe "%User Temp%\IRAR{random characters}.tmp\"
- {directory of WinRAR} a -r -epi1 "%User Temp%\IRAR{random characters}.tmp\" "{All Drives}\{Directory of archive}\{Name of archive(.zip or .rar)}"
- cmd /c RD /s /q "%User Temp%\IRAR{random characters}.tmp\"
(Note: %User Temp% is the current user's Temp folder, which is usually C:\Documents and Settings\{user name}\Local Settings\Temp on Windows 2000, XP, and Server 2003, or C:\Users\{user name}\AppData\Local\Temp on Windows Vista, 7, and 8.)
SOLUTION
9.850
14.882.03
20 Mar 2019
14.883.00
21 Mar 2019
Step 1
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 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 Worm.Win32.NITOL.AJP
- 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
Search and delete these folders
- %User Temp%\IRAR{random characters}.tmp
Step 5
Search and delete these files
- %User Temp%\hrl{random}.tmp
- %System%\{random}.exe
Step 6
Scan your computer with your Trend Micro product to delete files detected as Worm.Win32.NITOL.AJP. 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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