Malicious PDF — malware analysis report

Static analysis result for SHA-256 8af16dc5aa441f69…

MALICIOUS

PDF

74.7 KB Created: 2021-09-12 11:37:00 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: 260321f558e0d2c63a117940b5f513bc SHA-1: 03949758c026e5d981603b20427d5c068f4e6272 SHA-256: 8af16dc5aa441f690cfdd923520fe0cdb0d1463e076a8f65c951c94e00a55327
166 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains multiple external links, with several heuristics flagging it as a link farm on disposable hosting and containing algorithmically-generated URLs. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or distributing further malware. While no scripts were explicitly extracted, the PDF structure and URL patterns are consistent with spearphishing attachments designed to redirect users to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9840

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • PDF link to algorithmically-generated URL high PDF_RANDOM_URL_LINK
    PDF contains a clickable HTTP(S) link whose host looks algorithmically generated (pronounceable-random labels) and whose path/query carries a long high-entropy token. This is the randomized-redirector pattern of malspam phishing lures — the visible document is only a prompt — not a PDF parser vulnerability.
  • 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://adice-area.com/pictures/files/69881174813.pdf In PDF document text
    • https://eletmodguru.hu/files/files/nisumunutidibuwojo.pdfIn PDF document text
    • http://ambulatorioveterinariovianello.eu/userfiles/files/daluv.pdfIn PDF document text
    • http://klick-tipp.at/ckfinder/userfiles/publics/files/31866295526.pdfIn PDF document text
    • http://jessie.vn/images/ckeditor/files/surefolekoridedodefudu.pdfIn PDF document text
    • http://molenat-energies.fr/molenat.com/images/editor/file/biperemofixovexi.pdfIn PDF document text
    • https://nacituran.com/userfiles/file/jiwexefofosivulotavug.pdfIn PDF document text
    • http://leprofit.ee/cmsfile/contentfiles/jigukuriwomiwemali.pdfIn PDF document text
    • http://yule-sign.com/upload/editor/file/20210912002322.pdfIn PDF document text
    • http://newmob.it/userfiles/files/mifivowiwi.pdfIn PDF document text
    • https://sevsport.info/wp-content/plugins/super-forms/uploads/php/files/5ca4c14da8e3eda30dad5e84a8e95f13/zanipojowuxe.pdfIn PDF document text
    • https://haciendaloscipreses.cl/upload/file/rabunaworebopozo.pdfIn PDF document text
    • http://rakkhunnursinghome.com/user_img/files/sowulajixasapakinedebe.pdfIn PDF document text
    • http://nct-vn.com/userfiles/file/41367140869.pdfIn PDF document text
    • http://gyogytornasz.hu/editor_up/vesurimaxupaxafuwo.pdfIn PDF document text
    • http://mgtuae.com/uploads/file/10480865730.pdfIn PDF document text
    • https://glycocalyx.nl/userfiles/image/file/47652895974.pdfIn PDF document text
    • https://mahae.hu/files/files/xovetajetutipilexajiweri.pdfIn PDF document text
    • http://koryosushi.com/uploads/files/verolulizedi.pdfIn PDF document text
    • https://sunrise-photon.com/upfiles/editor/files/24268569165.pdfIn PDF document text
    • https://komunalno.vrgorac.hr/files/xuwisinokomuduj.pdfIn PDF document text
    • http://coffee33.ru/archive/file/89822200803.pdfIn PDF document text
    • http://obchodsezlatem.cz/upload/files/82458562513.pdfIn PDF document text
    • https://www.bouldersudbury.org/wp-content/plugins/formcraft/file-upload/server/content/files/161335a109b977---vumobaxaxoxobiti.pdfIn PDF document text
    • http://www.donboscovizag.org/images/files/84775329529.pdfIn PDF document text
    • https://indiantiffin4me.com/nbloom/fckuploads/file/55674064473.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/zMnd8XtcwSM/uplcv?utm_term=how+to+cast+mobile+with+tvPDF 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_off0000c281.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC281 10576 bytes
SHA-256: 0d06d2427c4eec965e548707d9951a59b8b5ef4168bb0bd306dc82f232d8b3b0
font_01_sfnt_off0000daad.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDAAD 16564 bytes
SHA-256: 8a36ef67b422a14bda7825473f663616250d2b04602ec9fe885409439e4f7189
font_02_sfnt_off00010549.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10549 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1