Malicious PDF — malware analysis report

Static analysis result for SHA-256 733be81767afba31…

MALICIOUS

PDF

86.8 KB Created: 2021-06-30 04:35:00 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-08-25
MD5: f596532568cd83bb8efa6c481ab18ea3 SHA-1: 8295518151a534a9ccc6bf81847353f8d10aae2b SHA-256: 733be81767afba31551e1fb6f1835e10d8b9932c6bbc29d0b57b4081e535e823
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF file flagged by ClamAV as Pdf.Phishing.Trojan and by an ML classifier as malicious. It contains numerous embedded URLs, many of which point to compromised websites or disposable hosting, suggesting a link farm designed to redirect users to malicious content. The presence of PDF_SEO_DISPOSABLE_LINK_FARM and PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM heuristics further supports this. No scripts were extracted, but the overall structure and URL patterns indicate a phishing or malware distribution attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9947

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 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 https://allytemp.ru/uplcv?utm_term=product+strategy+for+high+technology+companies+pdf PDF link annotation
    • http://rgn2u.com/userfiles/files/97690375377.pdfIn PDF document text
    • http://jfhcoaching.nl/userfiles/files/gumotikif.pdfIn PDF document text
    • https://bestrecycledautoparts.net/images_i/file/tixotemudumumatukubu.pdfIn PDF document text
    • https://arnetbilgisayar.com/upload/ckfinder/files/fuzozujofapos.pdfIn PDF document text
    • https://www.okcfarmersmarket.com/wp-content/plugins/super-forms/uploads/php/files/61c1d54d32c3eaaf3f232c2a1848ff94/nukuverofatobijemokejebe.pdfIn PDF document text
    • http://paillasse.hu/userfiles/file/96528869640.pdfIn PDF document text
    • http://wabasnb.com/files/fckeditor/file/193199290260b8a99c565a1.pdfIn PDF document text
    • http://jikaramen.com/uploads/files/98256139472.pdfIn PDF document text
    • https://ewms.vn/wp-content/plugins/super-forms/uploads/php/files/uk0l21hfm8er3vhpbqo3h6hsrm/losoneguxobiton.pdfIn PDF document text
    • https://markeishahall.com/wp-content/plugins/super-forms/uploads/php/files/cc58b75b6bef97bd2131a4e9eb3b80e6/96742301919.pdfIn PDF document text
    • http://erkerlaender.de/wp-content/plugins/formcraft/file-upload/server/content/files/160966fb9c1fb4---98270101229.pdfIn PDF document text
    • https://shared401k.com/wp-content/plugins/super-forms/uploads/php/files/36e0b2dc5e94940cb7d614543895efd7/66578124225.pdfIn PDF document text
    • http://www.bandungmesin.com/file/90652616598.pdfIn PDF document text
    • http://asu.com.vn/wp-content/plugins/super-forms/uploads/php/files/mhq6kai8kmic6l2t0caljqprfd/lazasabugivuzi.pdfIn PDF document text
    • https://flardochform.se/userfiles/file/46795075075.pdfIn PDF document text
    • http://www.justgiveahand.org/wp-content/plugins/formcraft/file-upload/server/content/files/160a9a4e97b85e---zizifamopixovuwejugagede.pdfIn PDF document text
    • http://artmetinc.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ad11f716bc6---zufarixigaxoj.pdfIn PDF document text
    • http://mfcwestenkwartier.nl/beta/userfiles/file/potamegiza.pdfIn PDF document text
    • https://immo-cjeanpaul.lu/userfiles/files/42031509672.pdfIn PDF document text
    • https://www.americansummercamps.com/wp-content/plugins/formcraft/file-upload/server/content/files/16084aa80ca2fe---17709170035.pdfIn PDF document text
    • http://uyaviation.com/wp-content/plugins/formcraft/file-upload/server/content/files/16081c2418f7e1---38976125730.pdfIn PDF document text
    • http://mijneigenlift.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160c0c4060d18b---lujixoke.pdfIn PDF document text
    • https://www.birdandwildlifeteam.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b9acc2c6e3a---xafubiziguriben.pdfIn PDF document text
    • http://degrossier.nl/uploads/file/86244333008.pdfIn PDF document text
    • 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_off0000f0f3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF0F3 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0001090a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1090A 11280 bytes
SHA-256: 30ca28458536977a282d3787070db8c5927d4cbd340055f0b5d86e32d90c834e
font_02_sfnt_off00012324.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12324 16356 bytes
SHA-256: 20f5ee101190998ad891617b3f1156728796fb4407c950674323e05f8f580f0d