ASEC Weekly Phishing Email Threat Trends (February 12th, 2023 – February 18th, 2023)

ASEC (AhnLab Security Emergency response Center) monitors phishing email threats with the ASEC automatic sample analysis system (RAPIT) and honeypot. This post will cover the cases of distribution of phishing emails during the week from February 12th, 2023 to February 18th, 2023 and provide statistical information on each type. Generally, phishing is cited as an attack that leaks users’ login account credentials by disguising as or impersonating an institute, company, or individual through social engineering methods. On a broader note, the act is a technical subterfuge that enables the threat actor to perform attacks such as information leaks, malware distribution, and fraud against various targets. The focus of this post will be on the fact that phishing attacks mainly occur through emails. We will also provide a detailed classification of various attack methods that are based on phishing emails. Furthermore, we will make an effort to minimize user damage by introducing new attack types that have never been found before and emails that require users’ caution, along with their keywords. The phishing emails covered in this post will only be those that have attachments. Emails that have malicious links in the body without attachments will be excluded.

Phishing Emails

During this week, the most prevalent threat type seen in phishing email attachments was FakePage, taking up 39%. FakePages are web pages where the threat actor has imitated the screen layout, logo, and font of the real login pages or advertising pages, leading users to enter their account and password information. The input information is sent to the threat actor’s C2 server or used to induce users to access other fake websites. See <FakePage C2> below It was then followed by Downloader with 28%, which includes loaders such as SmokeLoader and GuLoader. The third-in-line was Infostealer with 26%. Infostealer includes malware such as AgentTesla and FormBook, and they leak user credentials saved in web browsers, emails, and FTP clients. Aside from these, Trojan (9%), Backdoor (1%), Worm (1%), and Exploit (1%) types were detected.  The threat types using phishing email attachments and their order of prevalence are similar to the order of malware distribution published weekly in the <ASEC Weekly Malware Statistics>.

File Extensions in Phishing Emails

We have identified which file extensions were used by the threats above for the distribution of email attachments.  Some things to note for the phishing email attachments this week are the various compress file extensions that were used to hide malware. A total of 11 different types of extensions were used: ZIP, R00, RAR, R01, R17, GZ, DAA, XZ, Z, ACE, and LZH. As for FakePages, they were distributed with web pages scripts (HTML, HTM, SHTML) that must be executed with a web browser. Other malware, including Infostealer and downloader, came attached to emails with various file extensions including compressed files (ZIP, R00, RAR), IMG disk image files, DOCX, and PDF document files.

Cases of Distribution

The following are distribution cases that occurred during the week from February 12th, 2023 to February 18th, 2023. The cases will be classified into fake login pages and malware types, including Infostealer, Downloader, Exploit, and Backdoor. The numbers in email subjects and attachment filenames are unique IDs and may vary depending on the email recipient. Distribution cases with Korean subjects were also found. These are cases that specifically targeted Korean users instead of propagating themselves globally using the identical English subject and text.

Case: FakePage

Email SubjectAttachment
Scan Data from FX-1C7D2_16thFeb23Scan Data from FX-1C7D2_16thFeb23.PDF
All received emails have been deferred.***.com.html
FWD: Re: Wire Transfer ReceiptWire Transfer Receipt.shtml
Comprobante Fiscal Digital Febrero :ATT 15/02/2023 07:43:03 a. m.adjuntos_0102_.html
ST0RAGE QU0TA LIMIT EXCEEDED; Retreive your (47) New Pending Messages ✉ !!! On
DHL Shipping Document/Invoice ReceiptOriginal_Shipping_DOC#AWB.html
RE: SHIPPING DOCUMENT (Purchased Contract)FedExShipmentDoc.html
[Korean Air] Original Invoice CustomsOriginal-invoice_dhlee.htm
Re: Proof of payment deposited for invoicesInvoice.pdf.htm
[FedEx] Tax Invoice Notice (Tax Invoice)Tax-Invoice.html
New OrderNew Order.pdf
Payment has been scheduled to beneficiary on 13 Feb 2023Swift_Copy-rina.htm
The new file has been received successfully.Documents Folder.html
DHL Shipment Notification AWB No:: 48******16 Custom Form EConfirm Parcel AWB NO.48157-8578916.html
Re: Re: Quotation Request?Quotation Request.pdf
Re: Re: Outstanding Invoices for processingoutstandingPayment.INV.Shtml
Msa INQUIRY 21019612 dated 10-02-2023 – ReminderRFQV21019612.xls.shtml
[DHL Express] Guide on Submitting Import Clearance Info – AWB # – 394475043173DHL_Korea_AWB#394475043173.html
Invioce/New OrderPO.XJ210821Q.html
FedEx Notice on Import Tax Payment DeadlineFedEx-kskim.htm
AW: Fw: Payment Transfer Receipt #3142563Payment copy.shtml
: New ShipmentConfirm Shipment.htm
All received emails have been
PURCHASE ORDER & INVOICE-8750DOC -47059(2_15_2023 4_09_16 a.m.) Mixed Container.html
FW: Inv_0220238_from_WSFS LLCcomputer.PDF.shtml
Payment Advice for electronic wlre transfer – Ref: HSBC03481993/081639234Payment_adv.html
Re:Urgent payment orderPayment#adv.html
PCH-Ref-708U97SYY8Publishers Clearing House-2023.pdf

Case: Malware (Infostealer, Downloader, etc.)

Email SubjectAttachment
RE: RFQ – INQ-DOCCIA GRPORDER – DOCCIA #00071533.pdf(83KB).jar
Re EnquiryUPDATED ORDER.docx
Request for QuotationENQUIRY.IMG
FW: Request for QuotationENQUIRY.IMG
#Inquiry : 201820552Inquiry201820552.js
RE: FW: RE: RE: Material productions/ WorksheetMPSNTQWR90002023.IMG
FW: AUTHORIZATION LETTERwhatsapp20231302.gz
RE: Urgent – Payment Overdue SOASOA.gz
RFQ Order No 43456767RFQ_Order No
RE:Purchase OrderProduct_List.docx
DHL Shipment For Februray Notification : 45348693Original Shipping Documents.docx
Re DetailsPayment.docx
New Scanned document from Nedec Office PrinterScan_Copy264293.docx
Norcity OrderNorcity Sales order.docx
RE: Payment.Invoice copy.gz
PO-#2080M 2023Contract PO#2080.docx
RFQ:N20JLG| Invitation to quote for the supplyLORAN #N20JLG.docx
Zhangjiagang Ocean Favor_ Urgent QuotationRFQ.IMG
Reservation For RoomDetails for booking.docx
Quotation requiredRHK0876789-6789098.z
RE: ORDERSiemens Company Profile.img
DHL_DCO_Address changed_Pdf.exe
New:SHEKOU // INV. 2230887Commercial Invoice No. 2230887.pdf.z
Payment Copypayment
Payment is completedTT
PO #2302036 (kerisome)Purchase Order 2302036.r01
Payment InformationTTres2142023-pdf.gz
Re: Payment INV088002904SINOSwift Copy.rar
Re: Re: Re: Re: Re: Re: New ordernew order
APA Contract :RFQ 2023APA RFQ 2023.pdf.z
RE: RE: SOA_freight
funds for all inv. settledSKM20230216_$55580.88USD.ace
RE: CL/140/2023//: Customs Clearance BL_CI #SHIPPING – ATTENTIONBL_CL-2838374_3494432_Docx.XZ
Ref. IGA/PO/17493Ref. IGAPO17493.r00
AQMM General Trading LLC. LOIAQMM General Trading LLC LOI PDF1000.r00
Purchase OrderCatllog_00345_Pdf.exe
MONEY REQUIRETTres2152023-pdf.gz
Delivery Notifications_Fillin_003456…._Pdf.gz
Draft Copy Cont02983Draft_Copy_Cont02983.rar
Re: New Order Quotation – 0070086 – 23/16/02Order
PO#BO514 FEB/ 2023PO #BO514.z
Purchase Order//98462072Pur02958735_84ord.rar
Status of Payment
Confirmation & Draft DocumentsDRAFT INVOICE.GZ
Petek Debit Note LW-83322.DEBIT NOTE.LZH
Re[3]: very nice images privatefuck_action.pif
BBVA-Confirming Facturas Pagadas al VencimientoConfirmingPagadas.rar
RE: PO: 879204/1 FCR Draft 1 EFCR YAX1905070E-FCR Docs_pdf.gz
PROCESSIING CONTRCT SY2-WT2103-23.PS#049847646-4094876478MBN.001
RE: RE: Updated SOA 210827//: Statement 210826STATEMETNT OF ACCOUNT.rar
Cool Stuff!!Happy_XMas.eXe
AW: PO-000001306PO-000001306.IMG
MONEY REQUIREPurchase Order-pdf.gz
Re: Draft Docs Confirmation against PI#CK2023M1903DRAFT DOCS INVCK2023M1903 BL PL.xls
Re: SOA Detail Payment for shipment invoices from Nov 11th – Jan 12STATEMENT OF ACCOUNT CERIE 10134 Payment Advise.xls
By E-Mail send: Delotser Transport Operator – 00854377190085437719.IMG
RFQ-20000 TO 500000 MT/BARELLS TEST by SGSRFQ-20000 TO 500000 MTBARELLS TEST by SGSPDF.r00
FW: Technical Clarification No: 1TC 1 AHTSA 1093 1094 RO.xlsm
Re:invoice and PL 26/01/2023invoice and PL
Prompt ResponseDoubleClick to
ETSO Kodu hk.ETSO_ Kodunuz40Z000004399566L..exe.xz
Re: [Reject]RV: OFERTA PO# 000938882 NSSApplicationReject_68390(Jan31).one
PR.4828321- Request for Quotation | ATI HANDELS GmbHRFQ #4828321.doc
RE: Capital Tenders Group LTD PRICE REQUESTCapital Tenders Group LTD PRICE REQUEST DOC.r11
Nueva lista de pedidos y productos solicitados#Nueva lista de pedidos y productos solicitados.pdf.img
FOB Shenzhen price for its MOQFOB Shenzhen price for its MOQ.r02
FW: Invoice & Signed Contract -NEW ORDER-038408Invoice & Signed Contract 20230201.gz
FW: PO7574New Order PO039445.Pdf.exe
MONEY REQUIREttref01312023-pdf.gz
ENEL ITALIA SpA_RFQ12345HG7$$RFQ12345HG7Solar&Wind Procurement.r00
Paid Invoiceinvoice.pdf.z

The ASEC analysis team has selected keywords that users must look out for, based on the distribution cases above. If these keywords are included in the subject of the email, or if the same characteristics are found, users must exercise strict caution as they may be phishing emails from threat actors. 

Keywords to Beware of: ‘Delivery Notice’

The keywords for this week are ‘Delivery Notice’. The threat actor from last week distributed phishing emails with subjects containing “DHL Delivery Notice”. The sender of this phishing email used the email address of Korean Air. The typos and poor grammar of the text allow us to assume that it has been translated to Korean with machine translation. Inside the email is an attachment named “_Receipt_Pdf.gz”, and when this file decompressed, there is an EXE file with a name composed of random characters. This EXE file is an Inostealer. Users should practice caution when opening attachments in emails by checking for any strange extensions and poorly written Korean.

FakePage C2 URL

When users enter their IDs and passwords on the login pages among the FakePages created by the threat actor, their information is sent to the attacker’s server. The list below shows the threat actor’s C2 addresses of fake login pages distributed during the week.

  • hxxp[:]//technicallyjules[.]com/11/22/1/add[.]php
  • hxxp[:]//www[.]nrwolff[.]com[.]br/wp-admin/maint/bv/mxl[.]php
  • hxxp[:]//powertek[.]com[.]au[:]/mmmm/newppdfff[.]php
  • hxxp[:]//effervescible-safeg[.]000webhostapp[.]com//ace//ald[.]php
  • hxxp[:]//feurofood[.]com/wp-content/plugins/TOPXOH/index/index/1/add[.]php
  • hxxp[:]//formspree[.]io/f/xyyaekej
  • hxxp[:]//www[.]mannnheim[.]com/ek/fdpxoGur23f[.]php
  • hxxp[:]//kingrex[.]dreamhosters[.]com/krrs[.]php
  • hxxp[:]//chuwi[.]co[.]th/danzpihaypy/dhlpihaypy[.]php
  • hxxp[:]//qhuxon[.]gq/kiljoo/ond[.]php
  • hxxp[:]//submit-form[.]com/3pUBM45T
  • hxxp[:]//lucent-fittings[.]000webhostapp[.]com/action[.]php
  • hxxp[:]//groaning-sweepers[.]000webhostapp[.]com/PDF[.]php
  • hxxp[:]//riaxion[.]tech/www[.]Mail[.]ru_Verification/mail[.]php
  • hxxp[:]//himoil[.]com/var/gb[.]php
  • hxxp[:]//outdoorbuddies[.]org/xxx/newpdf1[.]php
  • hxxp[:]//yadavarionline[.]ir/wp-includes/otf/newppdfff[.]php

Attacks using phishing emails are disguised with content that can easily deceive users, such as invoices and tax payments, to induce users to access fake login pages or execute malware. Fake login pages are evolving by the second to closely resemble the original pages. The attackers pack malware in compressed file formats to escape the attachment scans of users’ security products. Users must practice strict caution and refer to recent cases of distribution to avoid being exposed to infection by malicious phishing emails. The ASEC analysis team recommends users follow the email security guidelines below.

  • Do not execute links and attachments in emails from unverified senders until they are proven to be credible.
  • Do not enter sensitive information such as login account credentials until the site is found to be reliable.
  • Do not execute attachments with unfamiliar file extensions until they are found to be reliable.
  • Use security products such as antimalware software.

According to the MITRE ATT&CK framework, phishing email attacks correspond to the following techniques.

  • Phishing for Information (Reconnaissance, ID: T1598[1])
  • Phishing (Initial Access, ID: TI1566[2])
  • Internal Spearphishing (Lateral Movement, ID:T1534[3])

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