Backdoor.Win32.Fynloski_0f489cab24

by malwarelabrobot on June 28th, 2013 in Malware Descriptions.

Trojan.SuspectCRC!IK (Emsisoft), Backdoor.Win32.Fynloski.FD, Trojan.Win32.Iconomon.FD, Trojan.Win32.Sasfis.FD, VirTool.Win32.DelfInject.FD, GenericInjector.YR, BackdoorFynloski.YR, GenericDownloader.YR, TrojanDownloaderAndromeda.YR (Lavasoft MAS)
Behaviour: Trojan-Downloader, Trojan, Backdoor, VirTool


The description has been automatically generated by Lavasoft Malware Analysis System and it may contain incomplete or inaccurate information.

Summary
Technical Details
Removal Recommendations

MD5: 0f489cab245cf3f7625eb4c7fde5663e
SHA1: eb8d85e1f80a584970a2b195fce6a3b397d73b6e
SHA256: f5ec4f30aa87d7a061d587aedf607549e6641450c338606339a9eb8a768a3f88
SSDeep: 12288:x7XpIMzFObKJUF4nF0dUst6nvA78IwNku6D/IukmjIInKGiFId:NuqyF4F05t6ve8Ii6LIukmjnIFm
Size: 571392 bytes
File type: PE32
Platform: WIN32
Entropy: Packed
PEID: MicrosoftVisualC; UPolyXv05_v6; NETexecutable
Company: no certificate found
Created at: 2013-05-18 16:35:17


Summary:

Trojan-Downloader. Trojan program, which downloads files from the Internet without user's notice and executes them.
Backdoor. Malware that enables a remote control of victim's machine.
VirTool. A program used to apply passive protection methods to viruses, such as obfuscation, encryption, polymorphism. The original virus is usually encrypted/compressed and stored inside the wrapper.

Process activity

The Backdoor creates the following process(es):

0f489cab245cf3f7625eb4c7fde5663e.exe:1772
tmp1.tmp.exe:356
tmp1.tmp.exe:1456

The Backdoor injects its code into the following process(es):

Vbc.exe:464

File activity

The process 0f489cab245cf3f7625eb4c7fde5663e.exe:1772 makes changes in a file system.
The Backdoor creates and/or writes to the following file(s):

%Documents and Settings%\%current user%\Local Settings\Temp\temp_ISZBdtKpyt\Vbc.exe (7547 bytes)
%Documents and Settings%\%current user%\Local Settings\Temp\tmp1.tmp.exe (1852 bytes)

The Backdoor deletes the following file(s):

%Documents and Settings%\%current user%\Local Settings\Temp\tmp1.tmp (0 bytes)

Registry activity

The process 0f489cab245cf3f7625eb4c7fde5663e.exe:1772 makes changes in a system registry.
The Backdoor creates and/or sets the following values in system registry:

[HKLM\SOFTWARE\Microsoft\Cryptography\RNG]
"Seed" = "26 AA F4 17 CF CA B4 35 2C 88 D5 84 24 CB F0 3D"

[HKCU\Software\Microsoft\Windows\CurrentVersion\Explorer\MountPoints2\{c155cd73-744b-11e2-8294-806d6172696f}]
"BaseClass" = "Drive"

[HKCU\Software\Microsoft\Windows\CurrentVersion\Explorer\Shell Folders]
"Cookies" = "%Documents and Settings%\%current user%\Cookies"

[HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Explorer\Shell Folders]
"Common Documents" = "%Documents and Settings%\All Users\Documents"

[HKCU\Software\Microsoft\Windows\CurrentVersion\Explorer\Shell Folders]
"Desktop" = "%Documents and Settings%\%current user%\Desktop"

[HKCU\Software\Microsoft\Windows\CurrentVersion\Explorer\MountPoints2\{c155cd72-744b-11e2-8294-806d6172696f}]
"BaseClass" = "Drive"

[HKCU\Software\Microsoft\Windows\CurrentVersion\Explorer\MountPoints2\{b98117e8-75ca-11e2-81b2-000c293708fb}]
"BaseClass" = "Drive"

[HKCU\Software\Microsoft\Windows\ShellNoRoam\MUICache\%Documents and Settings%\%current user%\Local Settings\Temp]
"tmp1.tmp.exe" = "ExtendScript2"

[HKCU\Software\Microsoft\Windows\CurrentVersion\Explorer\Shell Folders]
"AppData" = "%Documents and Settings%\%current user%\Application Data"

[HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Explorer\Shell Folders]
"Common Desktop" = "%Documents and Settings%\All Users\Desktop"

[HKCU\Software\Microsoft\Windows\CurrentVersion\Explorer\MountPoints2\{c155cd75-744b-11e2-8294-806d6172696f}]
"BaseClass" = "Drive"

[HKCU\Software\Microsoft\Windows\CurrentVersion\Explorer\Shell Folders]
"Cache" = "%Documents and Settings%\%current user%\Local Settings\Temporary Internet Files"

[HKCU\Software\Microsoft\Windows\CurrentVersion\Explorer\Shell Folders]
"Personal" = "%Documents and Settings%\%current user%\My Documents"

The Backdoor modifies IE settings for security zones to map all local web-nodes with no dots which do not refer to any zone to the Intranet Zone:

[HKCU\Software\Microsoft\Windows\CurrentVersion\Internet Settings\ZoneMap]
"UNCAsIntranet" = "1"

The Backdoor modifies IE settings for security zones to map all urls to the Intranet Zone:

[HKCU\Software\Microsoft\Windows\CurrentVersion\Internet Settings\ZoneMap]
"IntranetName" = "1"

The Backdoor modifies IE settings for security zones to map all web-nodes that bypassing proxy to the Intranet Zone:

[HKCU\Software\Microsoft\Windows\CurrentVersion\Internet Settings\ZoneMap]
"ProxyBypass" = "1"

The process Vbc.exe:464 makes changes in a system registry.
The Backdoor creates and/or sets the following values in system registry:

[HKLM\SOFTWARE\Microsoft\Cryptography\RNG]
"Seed" = "AE 03 3F 18 35 26 5A D1 02 9A 18 12 52 56 56 93"

The process tmp1.tmp.exe:356 makes changes in a system registry.
The Backdoor creates and/or sets the following values in system registry:

[HKLM\SOFTWARE\Microsoft\Cryptography\RNG]
"Seed" = "54 FC FE BD 06 43 8C 7A FF E0 4B AB DA B4 EE 20"

[HKCU\Software\Microsoft\Windows\CurrentVersion\Explorer\Shell Folders]
"AppData" = "%Documents and Settings%\%current user%\Application Data"

[HKCU\Software\Microsoft\Windows\CurrentVersion\Explorer\Shell Folders]
"Cache" = "%Documents and Settings%\%current user%\Local Settings\Temporary Internet Files"

To automatically run itself each time Windows is booted, the Backdoor adds the following link to its file to the system registry autorun key:

[HKCU\Software\Microsoft\Windows\CurrentVersion\Run]
"WinUpdate.exe" = "%Documents and Settings%\%current user%\Local Settings\Temp\tmp1.tmp.exe"

The process tmp1.tmp.exe:1456 makes changes in a system registry.
The Backdoor creates and/or sets the following values in system registry:

[HKLM\SOFTWARE\Microsoft\Cryptography\RNG]
"Seed" = "90 F0 50 43 84 7F 76 9D 36 8C 1A 9D BF 3B 19 FD"

[HKCU\Software\Microsoft\Windows\CurrentVersion\Explorer\MountPoints2\{c155cd73-744b-11e2-8294-806d6172696f}]
"BaseClass" = "Drive"

[HKCU\Software\Microsoft\Windows\CurrentVersion\Explorer\Shell Folders]
"Cookies" = "%Documents and Settings%\%current user%\Cookies"

[HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Explorer\Shell Folders]
"Common Documents" = "%Documents and Settings%\All Users\Documents"

[HKCU\Software\Microsoft\Windows\CurrentVersion\Explorer\Shell Folders]
"Desktop" = "%Documents and Settings%\%current user%\Desktop"

[HKCU\Software\Microsoft\Windows\CurrentVersion\Explorer\MountPoints2\{c155cd72-744b-11e2-8294-806d6172696f}]
"BaseClass" = "Drive"

[HKCU\Software\Microsoft\Windows\CurrentVersion\Explorer\MountPoints2\{b98117e8-75ca-11e2-81b2-000c293708fb}]
"BaseClass" = "Drive"

[HKCU\Software\Microsoft\Windows\CurrentVersion\Explorer\Shell Folders]
"AppData" = "%Documents and Settings%\%current user%\Application Data"

[HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Explorer\Shell Folders]
"Common Desktop" = "%Documents and Settings%\All Users\Desktop"

[HKCU\Software\Microsoft\Windows\CurrentVersion\Explorer\MountPoints2\{c155cd75-744b-11e2-8294-806d6172696f}]
"BaseClass" = "Drive"

[HKCU\Software\Microsoft\Windows\CurrentVersion\Explorer\Shell Folders]
"Cache" = "%Documents and Settings%\%current user%\Local Settings\Temporary Internet Files"

[HKCU\Software\Microsoft\Windows\CurrentVersion\Explorer\Shell Folders]
"Personal" = "%Documents and Settings%\%current user%\My Documents"

The Backdoor modifies IE settings for security zones to map all local web-nodes with no dots which do not refer to any zone to the Intranet Zone:

[HKCU\Software\Microsoft\Windows\CurrentVersion\Internet Settings\ZoneMap]
"UNCAsIntranet" = "1"

The Backdoor modifies IE settings for security zones to map all urls to the Intranet Zone:

[HKCU\Software\Microsoft\Windows\CurrentVersion\Internet Settings\ZoneMap]
"IntranetName" = "1"

The Backdoor modifies IE settings for security zones to map all web-nodes that bypassing proxy to the Intranet Zone:

[HKCU\Software\Microsoft\Windows\CurrentVersion\Internet Settings\ZoneMap]
"ProxyBypass" = "1"

Network activity (URLs)

URL: hxxp://dl-balancer.x.dropbox.com/FileToDownload.exe Country: United States
URL: dl.dropbox.com IP: 107.20.234.233
URL: ivandanko.no-ip.org IP: 31.38.9.54

Rootkit activity

No anomalies have been detected.

Propagation


Remove it with Ad-Aware

  1. Click (here) to download and install Ad-Aware Free Antivirus.
  2. Update the definition files.
  3. Run a full scan of your computer.


Manual removal*

  1. Terminate malicious process(es) (How to End a Process With the Task Manager):

    0f489cab245cf3f7625eb4c7fde5663e.exe:1772
    tmp1.tmp.exe:356
    tmp1.tmp.exe:1456

  2. Delete the original Backdoor file.
  3. Delete or disinfect the following files created/modified by the Backdoor:

    %Documents and Settings%\%current user%\Local Settings\Temp\temp_ISZBdtKpyt\Vbc.exe (7547 bytes)
    %Documents and Settings%\%current user%\Local Settings\Temp\tmp1.tmp.exe (1852 bytes)

  4. Delete the following value(s) in the autorun key (How to Work with System Registry):

    [HKCU\Software\Microsoft\Windows\CurrentVersion\Run]
    "WinUpdate.exe" = "%Documents and Settings%\%current user%\Local Settings\Temp\tmp1.tmp.exe"

  5. Clean the Temporary Internet Files folder, which may contain infected files (How to clean Temporary Internet Files folder).
  6. Reboot the computer.

*Manual removal may cause unexpected system behaviour and should be performed at your own risk.