AhnLab Security Emergency response Center (ASEC) 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 April 2nd, 2023 to April 8th, 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 with 47%. 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 The second most prevalent threat type was Downloader (18%), which includes loaders such as SmokeLoader and GuLoader. It was then followed by Worm (15%) and Infostealers (10%) like AgentTesla and FormBook that leak user credentials saved in web browsers, emails, and FTP clients. Aside from those mentioned above, Trojan (5%) and Dropper (5%) 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. FakePages were distributed through web pages script (HTM, HTML, SHTML) documents that must be executed with a web browser. Other malware, including Infostealer and downloader, came attached to emails with file extensions including compressed files (ZIP, 7Z, GZ, etc.).
Cases of Distribution
The following are distribution cases that occurred during the week from April 2nd, 2023 to April 8th, 2023. The cases will be classified into FakePage 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 identical English subject and texts.
Case: FakePage
| Email Subject | Attachment |
| RE: [****] ** number 1 & 2 EDM consultation related APCFS poster announcement material | NM.pdf |
| Access to your email will be restricted confirmation failed | fi***ce@*********.co.kr Update-2023.htm |
| RE: **** number 7 & 8 DeNOx facilities request for performance improvement estimate | MI.pdf |
| Re: [****] FGD pipe rack *** company plumbing Inform. request for forwarding and application | IR.pdf |
| FWD: [DHL] Notice on Import Tax Payment Deadline – (INV and AWB) | Original Shipping Doc#GM53726192.pdf.htm |
| Na*** Cou**** uploading all keywords | KTX.pdf |
| FW: purchase order attached | PO20230403.html |
| [External]FW: [******] Request to review affiliate service customer event | RA.pdf |
| User email disconnected from service | ********.****@*********.co.kr Update-2023.htm |
| FW: January 2019 Security Day content sharing | UT.pdf |
| [External]FW: [**] Request to issue certificate of career and disciplinary action form (***) | EN.pdf |
| RE: RE: RE: RE: ****) ** number 1 & 2 EDM consultation related surface SEM measurement photo | CT.pdf |
| SRPI Project quotation request | Specfication for SRPI Project.htm |
| Quotation QUO91019 | Quote.html |
| AIR WAY BILL – INVOICE AND PACKING LIST | AWB#.SHTML |
| New DHL Shipment Document Arrival Notice / Shipping Documents / Original BL, Invoice & Packing List | (DHL) Original BL, PL, CI Copies.htm |
| DHL Express | DHLSHIPPINGDOCS.htm |
| FedEx Shipment 811470484778: Parcel Scheduled For Delivery | Shipping Document.html |
| R: New offer request | scan001.htm |
| A Recent Charge on your Card was Unsuccessful | Account_Security _Message.htm |
| New DHL Shipment Document Arrival Notice: Shipping Documents, Original BL, Invoice & Packing List. | Tracking.html |
| THIS PURCHASE ORDER IS VRY URGENTLY NEEDED AND (TREAT IMPORTANT) | important#order.html |
| ACH Payment sent On: Monday, April 3, 2023 12:51 p.m. | Swift_Payment_Confirmation.pdf.shtml |
| Financial Statement /acc****ing@a*********.co.kr | Financial Statement.shtml |
| 【132nd Canton Fair】 | b****gu@*****.**.kr.htm |
| New Order | PO54324567.htm |
| PO#28124758 | 28124758.htm |
| ***@*********.co.kr sent you files via WeTransfer | WeTransfer files_*****ne@*********.co.kr.Htm |
| Re: ******.park You Have 1 New Shared Document | Truefriend_PAYMENT_CONTRACT.pdf |
| ACH Payment sent On:Thursday, April 6, 2023 1:43:27 PM | h***m@*********.com Voutcher.shtml |
| RE: IBK SWIFT PAYMENT COPY | IBKPaymentSwiftApproval.html |
| Purchase Order PO-3242 from VP Group Limited for sjlee | PO-3242.html |
| ACH Payment sent On:Thursday, April 6, 2023 3:20:47 PM | s***m@*********.com Voutcher.shtml |
| Re:Re:Re: Quotation order | New_Order Inquiry.Htm |
| Re : invoice for MARCH 2023 | REVISED INVOICE.shtml |
| Payment Transaction Notification : Success | optical PAYMENT ADVICE-US$ 168,573.htm |
| COMMERCIAL OFFER | COMMERCIAL OFFER.html |
| Your grant donation – {Mrs Jacquelline Fuller} | Donation Application.docx |
Case: Malware (Infostealer, Downloader, etc.)
| Email Subject | Attachment |
| Open outstanding account statement | Open account statement.PDF.jar |
| Attachment | NEW ENQUIRY-pdf.gz |
| Re: Re: Return invoice for Payment | Return invoice.rar |
| Pedido | Pedido040323.rar |
| [DHL] Acceptance of Import Declaration (Payment Before Acceptance) – 7759303436 | [DHL] 7759303436.rar |
| Your Shipment has Arrived Tracking Number! | Protected Copy Doc 099876858.rar |
| PO#40823-LiDe Industry Group Co Limited | PO#40823.rar |
| Request for quotation – lpr no. 8661 | RDA 8661 SEBASTIANO.rar |
| RE: RFQ-08-057-SAFETY SHOWER UNIT WITH COOLING SYSTEM | RFQ-08-057.rar |
| NEW ORDER PO # IF23029361209 | PO # IF23029361209.rar |
| RE: COSTCO Purchase Order #180222/CT24 & #160222/CT71 | COSTCO Purchase Order.rar |
| PURCHASE ORDER 163403 | Drawings.gz |
| Re: Fw: Payment for Outstanding Invoice | INV19384783.html |
| Fw: PAYMENTS | 20230406161956432901.zip |
| World Surfaris Remittance | balance$600,000.65-pdf.gz |
| Product Enquiry | SKM51092BY210.IMG |
| PO NO. 42236592 | PO#NO42236592000010.pdf.ARJ |
| WE WISH TO BUY THESE PRODUCTS | Product Listed.exe |
| SOA MARCH 2023 | SOA.xls |
| PAGO | JUSTIFICANTE DE PAGO.rar |
| Request from Octopus Asia Pacific | SKMB710925U10.xz |
| SumiP Machine equipment Inquiry | SUMIP MACHINE EQUIPMENT INQURIY.rar |
| Re[3]: super smart pics private | best_img.jpg.scr |
| Order List | Order-List.iso |
| Re: Document PO4377J7P | Document 54737.7z |
| Fwd: Re: Advanced Payment Confirmation | Advanced Payment – Ref_001299384596OBR11522.gz |
| KCI – Statement of Account – 30th march 2023 | statement for HADCO S.A.O.C.exe |
| Purchase Order PO GEC/PO/18667 for EHAF – KSA supply Project | PDF1567256210241910840.r01 |
| Deposit made to your account | Deposit slip.exe |
| FW:New PO#SPL036570 + RFQ036647 | New PO#SPL036570.pdf.GZ |
| Technical Datasheet | Technical_ Datasheet.7z |
| Re: Price Qoutation Request | RFQ 2008817838749.PDF.Z |
| Request for Quote | Request for Quote.PDF.7z |
| Payment Advice – Ref: [HSBC41057723] / RFQ Priority Payment | Payment Advice – Ref HSBC41057723 PDF.7Z |
| RE: Surat Pesanan – RFQ | PT.GLOBAL.PDF.rar |
| YOUR EMPLOYMENT STATUS | DETAILS AND INVOICES 4.rar |
| Payment receipt status | Payment_swift 20289820.pdf.gz |
| DHL AWB – Invoice & Shipping Documents | DHL AWB – Invoice & Shipping Documents.gz |
| sales contract-876 & New-Order | Executiveship PO 06042023.arj |
| Re:Top Urgent ORDER | New Order-3790028747.img |
| Angebotsanfrage | PO095657.zip |
| Re[5]: super wonderful images PRIVATE | best-phot.gif.scr |
| beautiful pictures | superimg.gif.scr |
| Re[5]: very cool pics | wildpic.gif.pif |
| Re[4]: super nice images don’t show | great_imgs.gif.exe |
| very wonderful photos only for you | private-pctrs.jpg.scr |
| Re[2]: very cool pics | greataction.gif.exe |
| sexy photos PRIVATE | privatepic.jpg.scr |
| super sexy pics PRIVATE | my-act.jpg.scr |
| Re[5]: very nice pictures very important | best_images.jpg.scr |
| Re[3]: smart photo FOR YOU ONLY | prv-pic.scr |
| super beautiful photo PRIVATE | my-images.jpg.pif |
| nice photos private | sexpctrs.pif |
| very nice photo | sex__phot.jpg.pif |
| nice pics | privatephot.gif.exe |
| Re[2]: nice picture imortant | great_images.exe |
| smart pictures | sexscene.exe |
| Re: super cool pics | great_act.jpg.pif |
| very cool picture PRIVATE | the_phot.gif.scr |
| wonderful photo | mypctrs.jpg.pif |
| sexy images | sexpic.jpg.pif |
| Re[3]: beautiful photo just for you | best__pctrs.gif.pif |
| very cool pics don’t show | the-plp.gif.exe |
| Re[2]: smart pictures | privphotos.jpg.scr |
| Re: smart pics | prvimgs.jpg.scr |
| sexy pics | myscene.pif |
| smart images | sexscene.scr |
| Re: very cool photos FOR YOU ONLY | great-img.scr |
| sexy pictures private | sexpctrs.exe |
| Re: cool picture imortant | prv__img.gif.scr |
| Re[4]: sexy images | privaction.exe |
| Re[2]: super smart pictures | fuckpctrs.jpg.scr |
| Re: super nice images only for you | great-pic.pif |
| Re: very nice photo | fuckphotos.gif.exe |
| beautiful pictures very important | sexaction.exe |
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: ‘PDF’
The keyword for this week is ‘PDF.’ For this week, the phishing emails attached with PDF files had titles including power plant equipment and were disguised as event promotional materials for certain companies. Instead of average documents such as invoices and purchase orders, the emails were disguised as being related to some power stations and equipment. As for the attached PDF files, their names and content were very similar despite the difference in the distributed emails’ names. The attachment names were a combination of two alphabets. When the file is viewed, it impersonates Microsoft Azure and prompts users to open it. When users click the open button, a page for entering the ID and password appears. Attempting to log in will result in account credentials being leaked to the attacker’s phishing server, as well as the user PC being infected with downloaded Qakbot malware. You can check for more details on this ASEC blog post (https://asec.ahnlab.com/en/51282/).
- Phishing URL: https[:]//rosatifragrances.co[.]zw/ei/ei.php
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.
- http[:]//demo[.]double-eleven[.]hk/wordpress/wp-content/plugins/6f7ecdf697634e1181a754ea4ca0913f/y/mm/mmd/index/fedex/FedExpress[.]php
- https[:]//newtrp[.]com/gbooonus/processor[.]php
- https[:]//formspree[.]io/f/myyazkbv
- https[:]//cranecenter[.]ru/Xx/cloudlog[.]php
- https[:]//www[.]btdpipe1ine[.]com/oc/fdpxoGur23f[.]php
- http[:]//www[.]znbs[.]co[.]zm/Uploads/Document/DHL/log[.]php
- https[:]//formbold[.]com/s/91wBz
- https[:]//chuyenphat[.]nascoexpress[.]com/wp-includes/noshaking/peeking[.]php
- https[:]//instelator-center[.]co[.]il/isso[.]checkerz[.]php
- http[:]//chikashikakehi[.]sakura[.]ne[.]jp/file/slot-gacor-maxwin/welcome[.]php
- http[:]//mail[.]alicevik[.]com[.]tr//makechina/lognet1[.]php
- https[:]//kazan-oil[.]ru/fidders/msms/vmxll[.]php
- https[:]//jaslyimpex[.]com/catalog/44/A/Excel[.]php
- https[:]//www[.]palazzocalo[.]com/cxHiEtx/Exc/Excell[.]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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The post ASEC Weekly Phishing Email Threat Trends (April 2nd, 2023 – April 8th, 2023) appeared first on ASEC BLOG.
Article Link: ASEC Weekly Phishing Email Threat Trends (April 2nd, 2023 – April 8th, 2023) - ASEC BLOG