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 August 15th, 2022 (Monday) to August 21st, 2022 (Sunday).
For the main category, info-stealer ranked top with 57.8%, followed by backdoor with 24.2%, downloader with 13.7%, ransomware with 3.7%, and CoinMiner with 0.6%.
Top 1 – Agent Tesla
AgentTesla is an infostealer that ranked first place with 38.5%. It is an info-stealer that leaks user credentials saved in web browsers, emails, and FTP clients.
It uses e-mail to leak collected information, and there are samples that used FTP or Discord API. C&C information of recently collected samples is as follows.
- server : mail.realforceshipping[.]com (65.254.34[.]162)
sender : info@realforceshipping[.]com
receiver : info@sialkotinstrumentsco[.]com
user : info@realforceshipping[.]com
pw : W*******018
- server : posta.ni.net[.]tr (89.252.128[.]115)
sender : email@example.com[.]tr
receiver : saleseuropower@yandex[.]com
user : firstname.lastname@example.org[.]tr
pw : nil****57
- server : mail.activandalucia[.]com (185.162.171[.]75)
sender : marketing9@activandalucia[.]com
receiver : sales9@activandalucia[.]com
user : marketing9@activandalucia[.]com
pw : iy*******6789@$
As most are distributed through spam emails disguised as invoices, shipment documents, and purchase orders, the file names contain such words shown above (Invoice, Shipment, P.O. – Purchase Order). Multiple collected samples were disguised as files with extensions of pdf and xlsx.
- JULY SOA.exe
- wire Transfers.exe
- Demand List.exe
- Oferta XL-PO5847_pdf.exe
- New Order.exe
Top 2 – Formbook
Formbook ranked second place with 9.3% (tied with RedLine).
Like other info-stealers, it is mainly distributed through spam emails. The distributed file names are close to each other.
- Purchase Order 2070121 SN-WS.Pdf.exe
- 6605701.xls .exe
- Payment Advice_pdf.exe
Formbook is injected into normal processes (one is a running explorer.exe and the other in system32) that performs malicious behaviors. Besides user credentials in the web browser, the malware can steal various information through keylogging, clipboard grabbing, and web browser form grabbing.
The following are the confirmed C&C server domains for Formbook:
Top 2 – RedLine
Along with Formbook, RedLine also ranked second place with 9.3%. The malware steals various information such as web browsers, FTP clients, cryptocurrency wallets, and PC settings. It can also download additional malware by receiving commands from the C&C server. Like BeamWinHTTP, there have been numerous cases of RedLine being distributed under the disguise of a software crack file.
The following are the confirmed C&C server domains for RedLine:
Top 4 – GuLoader
GuLoader, which ranked fourth place with 6.8%, is a downloader malware that downloads additional malware and runs it. It was packed with Visual Basic language in the past to bypass detection, but it is now distributed in a form of NSIS installer. It used to be known as CloudEye, but got the name GuLoader because Google Drive is frequently used as a download URL. In addition to Google Drive, various URLs such as One Drive from Microsoft and Discord can also be used.
Instead of being downloaded in a file form, GuLoader is downloaded on memory to avoid detection, and the downloaded file is encoded, not PE. It is then executed after being decoded in the memory, downloading malware such as infostealer (Formbook, AgentTesla) and RAT (Remcos, NanoCore).
As most are distributed through spam emails disguised as invoices, shipment documents, and purchase orders, 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.
- Seguimiento de Fedex.exe
- Orden de compra #20220510CO.exe
- Bairnliest Tabslisters.exe
- Afgiftsudvalgs Matrones.exe
- Invoice – PL.exe
Top 5 – AveMaria
AveMaria ranked fifth place with 6.2%. AveMaria is RAT (Remote Administration Tool) malware with remote control feature that receives commands from the C&C server and performs a variety of malicious behaviors.
AveMaria malware has been distributed via spam emails similar to AgentTesla, Lokibot, and Formbook malware. Additionally, it is packeted and distributed in a form of .NET to bypass detection. As such, the file names reported are not much different from those of other malware distributed through spam emails.
- PAYMENT SWIFT COPY.exe
- SCANN RFQ_887UHJ BASCO .INT.L.exe
The following are the confirmed C&C servers of AveMaria.
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