Malicious PDF — malware analysis report

Static analysis result for SHA-256 f31484f9b4d46d61…

MALICIOUS

PDF

83.8 KB Created: 2021-09-01 18:26:10 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 412d9c84170ad6d16620f23d21e5eab3 SHA-1: 53604eab522ef255620fe05d9401a9cd6c48ba1f SHA-256: f31484f9b4d46d61ecd86372fcec3874614c39e4e5304673c353883bdbe3573e
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, directing users to various external URLs, some hosted on compromised or disposable domains. The embedded URLs and the nature of the heuristics suggest an attempt to redirect users to phishing sites or download further malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9909

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 https://chcial.ru/uplcv?utm_term=editing+footnotes+in+word PDF link annotation
    • http://electronicaindex.nl/images/uploads/vituzepilipusoxeris.pdfIn PDF document text
    • https://www.orthovision-lublin.pl/ckfinder/userfiles/files/32862036626.pdfIn PDF document text
    • http://rideabikenews.com/user_img/files/99473581930.pdfIn PDF document text
    • https://tavio.ru/files/file/mixixorasoxedoxevubedelub.pdfIn PDF document text
    • https://thietbixaydungcantho.com/canthomobile2/public/images/sanpham/files/dapusoririwekepuzegobukuw.pdfIn PDF document text
    • https://www.americanapi.com/wp-content/plugins/formcraft/file-upload/server/content/files/160815f872fa96---13859943958.pdfIn PDF document text
    • http://pm-property.pl/userfiles/file/pusituvepizaxefugetuwo.pdfIn PDF document text
    • https://www.mclarenpress.com/wp-content/plugins/formcraft/file-upload/server/content/files/16079db20cd832---96677885026.pdfIn PDF document text
    • http://whuntex.info/userfiles/file/kusexiraxekavasodos.pdfIn PDF document text
    • http://nuyewrecruitment.com/wp-content/plugins/super-forms/uploads/php/files/4c0ec5ce90cd0ea3be47561589bfd40a/79256698919.pdfIn PDF document text
    • https://westcoastmovers.ca/wp-content/plugins/super-forms/uploads/php/files/h4pj7g4nb505h0qb02d2muv67v/rejobezefisusumesadus.pdfIn PDF document text
    • http://geoman.cz/data/file/zebebavani.pdfIn PDF document text
    • http://ebsenglish.net/_UploadFile/Images/file/86939537899.pdfIn PDF document text
    • https://noukos.gr/wp-content/plugins/formcraft/file-upload/server/content/files/160723d5e8a660---gepidezozekonogowonalaxok.pdfIn PDF document text
    • https://storage-in-motion.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ad305498640---58433611944.pdfIn PDF document text
    • http://mkconline.com/landmark/ckfinder/userfiles/files/31919168335.pdfIn PDF document text
    • http://kaies.net/upfiles/file/8442285928.pdfIn PDF document text
    • http://ombs.ru/uploads/files/57463311083.pdfIn PDF document text
    • https://www.physioaktivkramer.de/wp-content/plugins/formcraft/file-upload/server/content/files/16077481b8f3c7---88112175275.pdfIn PDF document text
    • https://lcd96.ru/wp-content/plugins/super-forms/uploads/php/files/1f20c453575fe9167890debf7ca4bcfc/gorilarisakurutulalas.pdfIn PDF document text
    • https://medok18.ru/wp-content/plugins/super-forms/uploads/php/files/f2bbb10f4f7ef27d736730bff642a747/82195233730.pdfIn PDF document text
    • https://byocamacho.com/ckfinder/userfiles/files/18931857669.pdfIn PDF document text
    • https://hsegroup.ru/wp-content/plugins/super-forms/uploads/php/files/p9dtphvodo9aqodiie2g3t11s2/telolalawotudenanok.pdfIn PDF document text
    • https://brunoamaranti.it/wp-content/plugins/super-forms/uploads/php/files/o9jpfb28tsasbpp5e0utsomc05/47647216980.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609ce70c5b017---zabagowos.pdfIn PDF document text
    • http://automsystem.com/UploadFile/file/20210726142724020.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_off0000e3bf.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE3BF 17632 bytes
SHA-256: 30936b20cebc621abcfab4fb0b0352eb3223168c0bd81e76c615ae443f4fda52
font_01_sfnt_off000110d0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x110D0 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000128e7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x128E7 10392 bytes
SHA-256: 0697a371cfd295b47543961d94815de64a579ba1d16c904583185d92d553bbad