Trojan.Win32.REMCOS.J

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.

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:

• %User Profile%\letfattelige\Signalklokken\Skaberglden
• %User Profile%\letfattelige\Signalklokken\Amitotically.kry
• %User Profile%\letfattelige\Signalklokken\Solanine
• %User Profile%\letfattelige\Signalklokken\Bonaght.bss
• %User Profile%\letfattelige\Signalklokken\Diskofilers16.lre
• %User Profile%\letfattelige\Signalklokken\Forsagelses31.ini
• %User Profile%\letfattelige\Encyklopdier\Heterotic.pre
• %User Profile%\letfattelige\Encyklopdier\Medlidenhedsdrabenes42.ini
• %User Profile%\letfattelige\Encyklopdier\Mimbar.ang
• %User Profile%\letfattelige\Encyklopdier\Quaestorship33.mol
• %User Profile%\letfattelige\Encyklopdier\Ramponfqr.fid
• %User Profile%\letfattelige\Encyklopdier\Remagnetization205.pse
• %User Profile%\letfattelige\Encyklopdier\Rigsarkivarer10.fun
• %User Profile%\letfattelige\Encyklopdier\Ruman.jpg
• %User Profile%\letfattelige\Encyklopdier\Starry.ove
• %User Profile%\letfattelige\Encyklopdier\Teglstensovne177.utt
• %User Profile%\letfattelige\Encyklopdier\Lsdel\Unhinge.lge
• %User Profile%\letfattelige\Encyklopdier\Lsdel\agurks.jpg
• %User Profile%\letfattelige\Encyklopdier\Lsdel\algors.rep
• %User Profile%\letfattelige\Encyklopdier\Lsdel\apothgm.jpg
• %User Profile%\letfattelige\Encyklopdier\Lsdel\Polychromizes\athene.gau
• %User Profile%\letfattelige\Encyklopdier\Lsdel\Polychromizes\avoyership.jpg
• %User Profile%\letfattelige\Encyklopdier\Lsdel\Polychromizes\belejreres.til
• %User Profile%\letfattelige\Encyklopdier\Lsdel\Polychromizes\bogense.sub
• %User Profile%\letfattelige\Encyklopdier\Lsdel\Polychromizes\chrisom.ing
• %User Profile%\letfattelige\Encyklopdier\Lsdel\Polychromizes\datalogiens.jpg
• %User Profile%\letfattelige\Encyklopdier\Lsdel\Polychromizes\feminologist.dem
• %User Profile%\letfattelige\Encyklopdier\Lsdel\Polychromizes\Udstillende\flyvestolenes.txt
• %User Profile%\letfattelige\Encyklopdier\Lsdel\Polychromizes\Udstillende\fremmedsprogsundervisningen.jpg
• %User Profile%\letfattelige\Encyklopdier\Lsdel\Polychromizes\Udstillende\Glideflugt\kdfoderfabrik.jac
• %User Profile%\letfattelige\Crenelled\kontaktparametre.sli
• %User Profile%\letfattelige\Crenelled\korporligt.txt
• %User Profile%\letfattelige\Crenelled\luskers.non
• %User Profile%\letfattelige\Crenelled\monotypes.tve
• %User Profile%\letfattelige\Crenelled\ndsignals.jpg
• %User Profile%\letfattelige\Crenelled\oligoplasmia.ben
• %User Profile%\letfattelige\Crenelled\randrusianere.ren
• %User Profile%\letfattelige\Crenelled\redigeringstasterne.ini
• %User Profile%\letfattelige\Crenelled\reformismens.ini
• %User Profile%\letfattelige\Crenelled\scoop.sam
• %User Profile%\letfattelige\Crenelled\skabergldernes.txt
• %User Profile%\letfattelige\Crenelled\trreplads.txt
• %User Profile%\letfattelige\Crenelled\wast.txt
• %User Temp%\ns{random}.tmp\System.dll
• %Public%\Pictures\aphyric.ini
• %Public%\Videos\chamottelers.ini
• %ProgramData%\Remcos\remcos.exe → copy of itself
• %User Temp%\ns{random}.tmp\System.dll → dropped by remcos.exe

(Note: %User Profile% is the current user's profile folder, which is usually C:\Documents and Settings\{user name} on Windows 2000(32-bit), XP, and Server 2003(32-bit), or C:\Users\{user name} on Windows Vista, 7, 8, 8.1, 2008(64-bit), 2012(64-bit) and 10(64-bit).. %User Temp% is the current user's Temp folder, which is usually C:\Documents and Settings\{user name}\Local Settings\Temp on Windows 2000(32-bit), XP, and Server 2003(32-bit), or C:\Users\{user name}\AppData\Local\Temp on Windows Vista, 7, 8, 8.1, 2008(64-bit), 2012(64-bit) and 10(64-bit).. %Public% is the folder that serves as a repository of files or folders common to all users, which is usually C:\Users\Public in Windows Vista, 7, and 8.. %ProgramData% is a version of the Program Files folder where any user on a multi-user computer can make changes to programs. This contains application data for all users. This is usually C:\ProgramData on Windows Vista, 7, 8, 8.1, 2008(64-bit), 2012(64-bit) and 10(64-bit), or C:\Documents and Settings\All Users on Windows Server 2003(32-bit), 2000(32-bit) and XP.)

It adds the following processes:

• %ProgramData%\Remcos\remcos.exe

(Note: %ProgramData% is a version of the Program Files folder where any user on a multi-user computer can make changes to programs. This contains application data for all users. This is usually C:\ProgramData on Windows Vista, 7, 8, 8.1, 2008(64-bit), 2012(64-bit) and 10(64-bit), or C:\Documents and Settings\All Users on Windows Server 2003(32-bit), 2000(32-bit) and XP.)

Other System Modifications

This Trojan modifies the following file(s):

• %User Temp%\ns{random}.tmp (multiple) → deleted afterwards

(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(32-bit), XP, and Server 2003(32-bit), or C:\Users\{user name}\AppData\Local\Temp on Windows Vista, 7, 8, 8.1, 2008(64-bit), 2012(64-bit) and 10(64-bit).)

It sets the attributes of the following files:

• %AppDataLocal%\Microsoft\Windows\Temporary Internet Files\Content.IE5 (Hidden)
• %AppDataLocal%\Microsoft\Windows\History\History.IE5 (Hidden)
• %Application Data%\Microsoft\Windows\Cookies (Hidden)

(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).. %Application Data% is the current user's Application Data folder, which is usually C:\Documents and Settings\{user name}\Application Data on Windows 2000(32-bit), XP, and Server 2003(32-bit), or C:\Users\{user name}\AppData\Roaming on Windows Vista, 7, 8, 8.1, 2008(64-bit), 2012(64-bit) and 10(64-bit).)

It modifies the following registry keys:

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
Rmc-XTJRJM = "%ProgramData%\Remcos\remcos.exe" → automatic execution every startup

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Run
Rmc-XTJRJM = "%ProgramData%\Remcos\remcos.exe" → automatic execution every startup

Download Routine

This Trojan connects to the following website(s) to download and execute a malicious file:

• https://drive.{BLOCKED}.com/uc?export=download&id=1P0H6gwE2eYN0AKtfr7DdavAQlP_Rro00 → downloads "vTGsVYV154.bin" if connection is successful
• https://drive.usercontent.{BLOCKED}.com/download?id=1P0H6gwE2eYN0AKtfr7DdavAQlP_Rro00&export=download → downloads "vTGsVYV154.bin" if connection is successful

Other Details

This Trojan adds the following registry keys:

HKEY_CURRENT_USER\Reinvestigating73\Uninstall\
kursusforlbs
Thymele26 = 1

HKEY_CURRENT_USER\Unadherently\Uninstall\
Hyperspiritualizings\preappointed
snotforvirredes = 0

HKEY_CURRENT_USER\vigtigpeteren\tillidsreprsentanter\
anesis
righters = FF B0 67 F0

HKEY_CURRENT_USER\Software\Rmc-XTJRJM
exepath = A1 AB 18 28 98 4B E0 28 45 90 1C FA 3C D0 BD 33 44 EB 9C CF FD 59 F4 E6 E7 3D 46 09 5B 4E 59 6D 7E 00 AD C1 20 34 24 59 65 93 C1 72 21 2B 59 93 BA B8 B4 F1 E2 0A 28 55 E8 A9 30 4F 7C CF 87 A7 77 B8

HKEY_CURRENT_USER\Software\Rmc-XTJRJM
licence = 986E875BFEEBBD0BC8A9A4B57AB05860

HKEY_CURRENT_USER\Software\Rmc-XTJRJM
time = {number}

HKEY_CURRENT_USER\Software\Rmc-XTJRJM
UID = {uid}