The ASEC analysis team is using the ASEC automatic analysis system RAPIT to categorize and respond to known malware. This post will list weekly statistics collected from June 14th, 2021 (Monday) to June 20th, 2021 (Sunday).
For the main category, info-stealer ranked top with 79.6%, followed by RAT (Remote Administration Tool) malware with 18.5%, and downloader with 1.9%.
Top 1 – AgentTesla
AgentTesla was ranked first place with 22.0%. It is an info-stealer malware that leaks user information saved in web browsers, e-mails, and FTP clients.
Recently collected samples use the following mail servers and user accounts when leaking the collected information.
- smtp.babcockvalve[.]com (208.91.198[.]143)
sender : ziara.landa@babcockvalve[.]com
receiver : ziara.landa@babcockvalve[.]com
user : ziara.landa@babcockvalve[.]com
pw : hA$***%9
- mail.necltd[.]com (207.244.65[.]197)
sender : mech1295@necltd[.]com
receiver : mech1295@necltd[.]com
user : mech1295@necltd[.]com
pw : @Navay***@
- smtp.globaloffs-site[.]com (208.91.199[.]223)
sender : staffs@globaloffs-site[.]com
receiver : staffs@globaloffs-site[.]com
user : staffs@globaloffs-site[.]com
pw : yLxC***2
As most are distributed through spam mails disguised as invoice, shipment document, and purchase order, the file names contain such words shown above (Invoice, Shipment, P.O. – Purchase Order). Some samples have extensions disguised as document files such as pdf and xlsx or Auto CAD blueprint files such as dwg.
- new inquiry.exe
- SWIFT Transfer (103) 000000886106.exe
- Seoulkorea KCTC International Ltd.exe
- RFQ REF R2100131410.pdf.exe
- #RFQ Price List.exe
- 201910152133Purchase Order (New)_10115_GIT_0.exe
- Company Registration Form.exe
- SHIP’S PARTICULARS.pdf.docx.exe
- Amended order 210617.pdf.exe
Top 2 – Formbook
Formbook is an info-stealer malware ranked in second place with 17.5%.
Like other info-stealer malware, it is mainly distributed through spam mails. The distributed file names are close to each other.
- Drawings – xls.exe
- Proforma invoice EUR-398746345334.pdf.exe
- Poczta Polska Informacje o transakcjach2021.exe
As Formbook is injected in a normal process that is in the directory of explorer.exe and system32, the malicious behaviors are performed by the normal process. Besides user account information in the web browser, the malware can steal various information through keylogging, clipboard grabbing, and web browser form grabbing. Below is the list of confirmed C&C server URLs of Formbook.
Top 3 – Lokibot
This week, Lokibot ranked third place with 16.7%. It is an info-stealer malware that leaks information about programs such as web browsers, mail clients, and FTP clients.
Being a malware that is distributed through spam mails, it shares similar distributed file names with other malware that are distributed through spam mails.
- Purchase Order (New)_10115_[SANNER]_210617.exe
- Estimate Request_BK210617.exe
- custom invoice june AIT.exe
- Purchase Order (New)_10115_GIT_210616.exe
- IRASAN TERMINAL INFORMATION.pdf.exe
As shown in the below, most Lokibot C&C server URLs tend to end in fre.php.
Top 4 – CryptBot
CryptBot malware ranked fourth place with 14.0%. The malware is downloaded through PUP programs and has features of stealing additional information and downloading additional malware.
It is mainly distributed from phishing sites disguised as utility program download pages which are shown when searching certain keywords in Google.
The following are the confirmed C&C server URLs and additional malware download URLs of CryptBot.
- C&C1 : hxxp://olmxqj73,top/index,php
C&C2 : hxxp://morayp07,top/index,php
DownloadURL : hxxp://vamalv10,top/download,php?file=lv,exe
- C&C1 : hxxp://kiyfsx16,top/index,php
C&C2 : hxxp://mormbl01,top/index,php
DownloadURL : hxxp://peoldb01,top/download,php?file=lv,exe
- C&C1 : hxxp://olmdge23,top/index,php
C&C2 : hxxp://mortyl02,top/index,php
DownloadURL : hxxp://vamzxy03,top/download,php?file=lv,exe
The filenames distributed from phishing sites disguised as utility program download pages are as follows.
Top 5 – NanoCore
NanoCore ranked fifth place with 6.8%. It is a RAT malware developed with .NET. Like njRAT, it can perform various commands given by the attacker such as information leakage including keylogging.
Similar to AgentTesla, Formbook, AveMaria, and Remcos, the NanoCore is packed with .NET packing and distributed through attached files in spam mails. As such, the file names reported are not much different from those of other malware distributed through spam mails.
- Order EA566821.exe
The following list is the confirmed C&C server domains for NanoCore.