Malicious PDF — malware analysis report

Static analysis result for SHA-256 a3d30143349745ff…

MALICIOUS

PDF

81.1 KB Created: 2021-09-19 21:59:13 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: dcfcc45697265295de3b354c43d1fb99 SHA-1: 7cd5e33d96dfac72abac8a62079c290ee21a0ddd SHA-256: a3d30143349745ff47af11c172312a3a2e00450043e6bf803b7500e9bbb91572
156 Risk Score

Malware Insights

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

The PDF file was flagged by multiple heuristics and a machine learning classifier as malicious, with ClamAV identifying it as a phishing trojan. The presence of a link farm, including links to compromised CMS upload storage and disposable hosting, strongly suggests a phishing or malware distribution attempt. The document body is heavily obfuscated and contains metadata indicating it was generated by wkhtmltopdf, which is not typical for legitimate documents.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9955

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://kowel.com/ckfinder/userfiles/files/1631819704.pdf In PDF document text
    • https://www.psk.com.au/application/third_party/ckfinder/userfiles/files/34246489965.pdfIn PDF document text
    • https://oancora.com/ckfinder/files/4301112143.pdfIn PDF document text
    • http://ultraljud.nu/bild/files/girudu.pdfIn PDF document text
    • https://grandegroup.net/files/15853392595.pdfIn PDF document text
    • https://kemxoi.vn/app/webroot/files/images/pages/files/47926615099.pdfIn PDF document text
    • http://www.aportecnica.com/imagenes/editor/file/3223995215.pdfIn PDF document text
    • https://arkadas.yuzuktr.com/eskortarama.com/resimler/file/lavewetipude.pdfIn PDF document text
    • https://patidarpalanpur.com/web/k/main_admin/ckfinder/userfiles/files/9614278548.pdfIn PDF document text
    • https://www.carlosfunes.es/wp-content/plugins/formcraft/file-upload/server/content/files/16138cd11f2ef3---82565965310.pdfIn PDF document text
    • https://mymovingestimate.com/wp-content/plugins/super-forms/uploads/php/files/120271ceabeb9c5ed938257b3d2a479d/dajuvunuvuba.pdfIn PDF document text
    • https://saftanton.dk/wp-content/plugins/formcraft/file-upload/server/content/files/161408e85bc85b---kiweviwiga.pdfIn PDF document text
    • https://ksi-system.pl/editorfiles/file/27297987944.pdfIn PDF document text
    • http://www.kizkulesikizogrenciyurdu.com/public/ckfinderuploads/files/zufaxizosorezijel.pdfIn PDF document text
    • http://keitbg.com/images/files/bukulumodavoxebe.pdfIn PDF document text
    • https://viboot.traigiongthuha.com/ckfinder/userfiles/files/sovenaguno.pdfIn PDF document text
    • http://laihoawedding.com/app/webroot/upload/files/nidujegizam.pdfIn PDF document text
    • http://another-partner.morefriendship.com/upload/files/19776248043.pdfIn PDF document text
    • http://www.psstrecno.sk/wp-content/plugins/formcraft/file-upload/server/content/files/1612ffce588dd3---13876971399.pdfIn PDF document text
    • https://skvely-kup.cz/files/file/11332198720.pdfIn PDF document text
    • http://kehlux.lu/userfiles/files/bomiwunivux.pdfIn PDF document text
    • https://bawauang.com/contents/files/33201832635.pdfIn PDF document text
    • http://cofetariafraguta.ro/UserFiles/file/fabavofum.pdfIn PDF document text
    • https://newcar-rental.com/uploads/files/202109012321329682.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/BkSY9tpko7c/uplcv?utm_term=free+download+photoshop+cs3+full+crackPDF 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_off0000d78e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD78E 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000efa0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEFA0 17592 bytes
SHA-256: 1f849721121f5cc0804e44c20d8b1082b9f31b3048641bd12c4f04ca1f1b1463
font_02_sfnt_off00011cee.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11CEE 11052 bytes
SHA-256: 268ce578f19963c22b663c22c5ad955d142cb22867662364665e2fd8a50fac5c