AhnLab Security response Center (ASEC) uses the ASEC automatic analysis system RAPIT to categorize and respond to known malware. This post will list weekly statistics collected from March 20th, 2023 (Monday) to March 26th, 2023 (Sunday).
For the main category, backdoor ranked top with 41.7%, followed by downloader with 31.9%, Infostealer with 24.7%, ransomware with 1.1%, backing with 0.3%, and CoinMiner with 0.3%.
Top 1 – Redline
RedLine ranked first place with 35.6%. 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 2 – Amadey
This week, Amadey Bot ranked second place with 12.2%. Amadey is a downloader that can receive commands from the attacker to download additional malware, and when info-stealing modules are used, it can collect user credentials in the infected system.
Usually, Amadey is installed by SmokeLoader which is distributed in the disguise of normal programs and crack malware. In the recent days, however, Amadey is being distributed to corporate users through malicious document files attached to spam mails and being used to install LockBit ransomware.
Top 3 – AgentTesla (Tied)
AgentTesla is an Infostealer that ranked third place with 10.3% (tied with BeamWinHTTP). It leaks user credentials saved in web browsers, emails, and FTP clients.
Although it uses emails (a.k.a. SMTP protocol) to leak collected information, there are samples that used FTP or Telegram API. The C&C information of recently collected samples is as follows.
- SMTP Server : mail.ppecindia[.]com
User : firstname.lastname@example.org
Password : acco******23$
Receiver : accounts@ppecindia[.]com
- SMTP Server : mail.alnajimalzahir[.]com
User : email@example.com
Password : Se********xz
Receiver : ali.dcc@alnajimalzahir[.]com
- Telegram : hxxps://api.telegram[.]org/bot5693068931:AAGSQSNIWDJM1FzeZVNHS020I9wVBrQdkRM/
- Telegram : hxxps://api.telegram[.]org/bot5687731944:AAEDpsUftmaHrKNSGkOlhq0UZLPEvIUd8Bo/
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, and P.O. – Purchase Order). Multiple collected samples were disguised as files with extensions of pdf and xlsx.
- New 2023 Prices List.exe
- Bank Transaction Activity.exe
- payment details.exe
- Original Documents.exe
- invoice copy.pdf.exe
- Outstanding Details.exe
Top 3 – BeamWinHTTP (Tied)
BeamWinHTTP is a downloader malware that ranked third place with 10.3% (tied with AgentTesla). The malware is distributed via malware disguised as PUP installer. When it is executed, it installs PUP malware Garbage Cleaner and can download and install additional malware at the same time.
Top 5 – Guloader
GuLoader, which ranked fifth place with 5.3%, is a downloader malware that downloads and executes additional malware. It was packed with Visual Basic language in the past to bypass detection, but it is now distributed in a form of an 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 Infostealers (Formbook and AgentTesla) and RAT (Remcos and 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, and 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.
- JUSTIFICANTE DE PAGO.exe
- justificante de transferencia.exe
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