Malicious PDF — malware analysis report

Static analysis result for SHA-256 621d5357e6bfd76b…

MALICIOUS

PDF

80.1 KB Created: 2021-09-24 10:11:34 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: d8ea79ccf5398c7481c83cef68a2e500 SHA-1: 53862991fb120e30801e77c7b6a83c7e78b003fc SHA-256: 621d5357e6bfd76ba1943304851888a3a149d643bb0b11f63f04f743d04adcfc
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF contains numerous embedded URLs, many of which point to compromised CMS uploads or disposable hosting, indicating a link farm designed to distribute malicious content. The ML classifier and ClamAV detection strongly suggest a phishing or trojan payload. The primary attack pattern involves luring users to click on these links, potentially leading to further compromise.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • PDF link farm points to compromised-WordPress upload storage medium PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM
    PDF contains multiple clickable links, across many distinct hosts, whose targets are random-slug files parked in the upload directories of vulnerable WordPress form plugins (FormCraft, Super Forms). This is the hallmark of the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains hosted on compromised sites. The PDF itself carries no exploit — the risk is the linked destinations.
  • Small PDF is a non-clustered link farm on disposable hosting medium PDF_SEO_DISPOSABLE_LINK_FARM
    Small PDF contains many clickable external PDF links spread thin across many distinct hosts (no single dominant host), corroborated by a utm_term SEO-redirector link and/or links parked on free/disposable content hosts. This is the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains, rather than a normal document citation pattern. The PDF itself carries no exploit — the risk is the linked destinations.
  • External URI info PDF_URI
    PDF contains an external URL action
  • Object number defined twice with different bodies info PDF_DUPLICATE_OBJ_BODY_INCREMENTAL
    The same indirect object (N G) is defined more than once with different body bytes. First-wins and last-wins readers will resolve different content, which is a parser-confusion shape used by targeted PDFs. Body-only differences are common in benign incremental updates, so severity is raised only when the duplicate carries active content.
  • Embedded URL info EMBEDDED_URL
    One or more URLs were extracted from the document. The URL itself is not a detection — see the per-URL labels for which channel (macro, JS, link annotation, document body, ...) reached each URL.
    URL http://myphamasia.net/upload/files/bofekilososexubake.pdf In PDF document text
    • https://thai-airpark.com/ckfinder/userfiles/files/tuxuku.pdfIn PDF document text
    • https://timavoshipsupply.it/userfiles/file/90591487275.pdfIn PDF document text
    • http://www.mustwalge.ee/data/content/files/56728080341.pdfIn PDF document text
    • http://cdwy028.com/uploadfile/file/20210916130839.pdfIn PDF document text
    • https://cytokin.ca/upload/editor/file/57203297487.pdfIn PDF document text
    • https://fnb-concepts.com/images/uploads/files/fumekiparak.pdfIn PDF document text
    • https://bisleri.genefied.co/ckfinder/userfiles/files/nazimowukowevi.pdfIn PDF document text
    • http://starwindows.ie/ckfinder/userfiles/files/27448151652.pdfIn PDF document text
    • http://worksafeorg.com/wp-content/plugins/super-forms/uploads/php/files/1g8thihf3837uckbrnp92kg6f6/nitexo.pdfIn PDF document text
    • http://escolacaritas.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613644efc0e5c---8979927512.pdfIn PDF document text
    • http://3handseg.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613a81cae3bed---28817237849.pdfIn PDF document text
    • http://diennuocdanang.com/uploads/image/files/85450182658.pdfIn PDF document text
    • http://zulassungsservice4you.de/bilder/file/wewikepod.pdfIn PDF document text
    • https://eletroluz-al.com/_IMG/img_internas/file/tenide.pdfIn PDF document text
    • http://behtarinekhodetbash.com/files/files/birasilumamuvomuvijuxina.pdfIn PDF document text
    • http://deeringbayrealestate.com/userfiles/files/83172859943.pdfIn PDF document text
    • http://zeroseistudio.eu/userfiles/files/88898973468.pdfIn PDF document text
    • https://regaluxiluminacion.com/uploads/assets/file/visur.pdfIn PDF document text
    • https://windfreeklima.com/upload/ckfinder/files/wofelunekogukew.pdfIn PDF document text
    • http://trip-sale.ru/userfiles/file/guxonazewovuforubikoz.pdfIn PDF document text
    • http://marchmontnews.com/imgs/file/nitivakokesisalukazifo.pdfIn PDF document text
    • http://vinacafe-dalat.com/Images_upload/files/nedobijirurafajevipijida.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/FevRqgeaUVY/uplcv?utm_term=80+mindset+20+skills+book+pdfPDF link annotation
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#In PDF document text
    • http://purl.org/dc/elements/1.1/In PDF document text
    • http://ns.adobe.com/pdf/1.3/In PDF document text
    • http://ns.adobe.com/xap/1.0/In PDF document text
    • http://ns.adobe.com/xap/1.0/mm/In PDF document text
    • http://ns.adobe.com/xap/1.0/rights/In PDF document text
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000d456.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD456 17348 bytes
SHA-256: 927fd74039d0629944a5bf5899da68b40d04483f651fac9cfbf9eef320fbd229
font_01_sfnt_off00010147.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10147 10984 bytes
SHA-256: 9d182ec143b7d75f2469993859f4b3bb0f8b3a8cbdfa0e75d1ec6bcf119edcbd
font_02_sfnt_off00011a8a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11A8A 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1