Malicious PDF — malware analysis report

Static analysis result for SHA-256 a89f72d39e1179cf…

MALICIOUS

PDF

71.8 KB Created: 2021-10-07 18:48:26 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: 009280ff2c97f6c3106eb7b212a39696 SHA-1: fe8229fc8e89172efde29a6abf9a29f09e0f49a3 SHA-256: a89f72d39e1179cfb4b8bab96a5821d33a440d6f51fb84149ec706a6d21598ae
156 Risk Score

Malware Insights

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

The PDF file contains numerous embedded URLs, many of which point to compromised CMS uploads or are part of a link farm on disposable hosting. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for SEO poisoning or directing users to malicious content. The document body is heavily obfuscated and does not provide direct textual clues, but the heuristic findings are sufficient to determine the attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

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://huntic.ru/uplcv?utm_term=organisational+features+of+text PDF link annotation
    • https://edenestates.com/ckfinder/userfiles/files/17050544316.pdfIn PDF document text
    • https://adverto.ee/userfiles/file/kadikebogejuk.pdfIn PDF document text
    • http://nikolalepojevic5.com/multimedia/file/84211185136.pdfIn PDF document text
    • https://fairtradeportal.pl/userfiles/file/buwegitiwuxapebetos.pdfIn PDF document text
    • https://beleznayauto.hu/galeria/pictures/jurodazebadabaker.pdfIn PDF document text
    • http://vp-dmsh.ru/admin/ckfinder/userfiles/files/28738450113.pdfIn PDF document text
    • http://buzmakov-ua.ru/admin/ckfinder/userfiles/files/dolojejomukiv.pdfIn PDF document text
    • https://microfocus-realize2020mea.com/wp-content/plugins/super-forms/uploads/php/files/3f83503fc8eb00644a153e8951a53640/getupiputun.pdfIn PDF document text
    • https://listapp.in/ci/userfiles/files/buriwefuvokuzufix.pdfIn PDF document text
    • http://nasledie-sluck.by/var/upload/file/74790189327.pdfIn PDF document text
    • https://luxm.pl/userfiles/file/57540431460.pdfIn PDF document text
    • http://sqc.jp/user_data/editor/ckfinder/core/connector/php/upload/files/54906265377.pdfIn PDF document text
    • http://wamaeassociates.com/images/uploads/originals/file/lifele.pdfIn PDF document text
    • https://mindweave.co.uk/wp-content/plugins/super-forms/uploads/php/files/m2g7fcfi9jdkkk6cqj4ioia7qj/71834842569.pdfIn PDF document text
    • http://jysfh.com/upload_fck/file/2021-9-21/20210921065934947886.pdfIn PDF document text
    • http://manpukuorder.com/uploads/files/tefevutu.pdfIn PDF document text
    • https://ra7a7p-h3ba7.com/contents/files/77380066811.pdfIn PDF document text
    • http://efuegypt.org/userfiles/file/lodurofojoberetezakubibin.pdfIn PDF document text
    • http://www.americaninvest.net/upls/files/25516295105.pdfIn PDF document text
    • http://woodwork.pl/ubezpiecz/obrazy/file/kisokavubawixizogusara.pdfIn PDF document text
    • https://www.borzabadi.com/ckfinder/userfiles/files/98511002147.pdfIn PDF document text
    • http://bk-plus.at/userfiles/files/vepatefenen.pdfIn PDF document text
    • https://gencerenerji.com/resimler/files/91636664181.pdfIn PDF document text
    • http://admio.ru/wp-content/plugins/formcraft/file-upload/server/content/files/161447cc9873e5---dusipofekajabewegesipot.pdfIn PDF document text
    • http://www.accessibilite-salle-eau.com/ckfinder/userfiles/files/sufuzimig.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_off0000b981.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB981 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000d198.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD198 10616 bytes
SHA-256: bd6078d808243aa86d14c95b5135d5a0317c491886515e7f9cd8139c8f64168d
font_02_sfnt_off0000ea0a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEA0A 15600 bytes
SHA-256: d916fdb4e5a363841dbe7110798468b638fa733b5a0062abf25b64f4f70ead2c