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 27th, 2022 (Monday) to July 3rd, 2022 (Sunday).
For the main category, info-stealer ranked top with 48.0%, followed by banking malware with 26.5%, RAT (Remote Administration Tool) with 12.5%, downloader with 8.2%, ransomware with 2.2%, coinminer with 1.8%, and backdoor with 0.7%.
Top 1 – AgentTesla
AgentTesla is an infostealer that ranked first place with 29.7%. 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.nec-eg[.]com (23.235.222[.]9)
sender : sales5@nec-eg[.]com
receiver : nelsonpacavira01@gmail[.]com
user : sales5@nec-eg[.]com
pw : i!N****12
- server : mail.anora-il.com (66.85.132[.]138)
sender : email@example.com
receiver : firstname.lastname@example.org
user : email@example.com
pw : ikec***89@@$$
- server : smtp.jubana[.]cam (103.6.198[.]52)
sender : firstname.lastname@example.org
receiver : email@example.com
user : firstname.lastname@example.org
pw : mpr*****456
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.
- confirm order.exe
- 2022 Amortization PDF.exe
- Payment Confirmation – 16326978.exe
- JULY PRODUCTION PLAN.exe
- DRAFT DOCUMENTS.exe
Top 2 – Formbook
Formbook ranked second place with 20.3%.
Like other info-stealer, it is mainly distributed through spam emails. The distributed file names are close to each other.
- BL & jpg.exe
- Copy656287HG PDF.exe
- Payment slip.exe
- INV No. SMEPL03122-23 & PL.pdf.exe
- Statement of Accoun 2022 06 29.exe
- MV.WHITE TOKIO (TWEEN DECK).exe
- PURCHASE ORDER 87910219.exe
As Formbook is injected into two normal processes (one is explorer.exe and the other in system32 directory), the malicious behaviors are performed by the normal process. Besides user credentials 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 – Emotet
Emotet ranked third place with 12.3%. Emotet is a banking malware that is being continuously distributed via spam mails.
In its basic form, it is a downloader without additional features, but once installed on a system, it can download additional modules or additional malware.
Additional modules include user info-stealing modules that steal information such as web browser and e-mail credentials, and propagation module that spreads via shared folders. Additional malware strains include other banking malware such as Qakbot and Trickbot.
Top 4 – GuLoader
GuLoader, which ranked fourth place with 10.4%, is a downloader malware that downloads and runs additional malware. It was packed with Visual Basic language in the past to avoid detection, but it is now distributed in a form of NSIS installer. It used to be known as CloudEye, but named GuLoader because Google Drive is frequently used as a download URL. In addition to Google Drive, various URLs such as One Drive from Microsoft can also be used.
Instead of being downloaded in a file form, GuLoader is downloaded on memory to avoid detection, and downloaded file is encoded, not PE. It then runs after decoding 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.
- V & W Ventures Order_pdf.exe
- ADNOC RFQ 97571784_pdf.exe
- Over Due SOA.pdf.exe
- transfer copy pdf.exe
Top 5 – Lokibot
Lokibot malware ranked fifth place with 6.6%. It is an info-stealer that leaks information about programs such as web browsers, email clients, and FTP clients.
Being a malware that is distributed through spam emails, it shares similar file names with other malware spam emails.
- RE-ORDER RFQ.exe
- DHL Receipt_AWB811470484778.exe
- WIRA_BAJA_MAKMUR MANDIRI_Dp_Full_PO_2201090_REVISED_PI_LPE20220616.pdf.exe
As shown below, most Lokibot C&C server URLs tend to end in fre.php.
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