Malicious PDF — malware analysis report

Static analysis result for SHA-256 4f18da17da9dffd7…

MALICIOUS

PDF

71.7 KB Created: 2021-09-19 02:52:39 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 972c754884f42fe8ee0219790edca980 SHA-1: 5075fdbfafd86e4842f5be3a6ace475a872952be SHA-256: 4f18da17da9dffd724a857f7d0b94fc6428d5799b11759f147604b7d87e4eea3
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. It contains a large number of embedded URLs, many of which point to compromised WordPress sites or disposable hosting, suggesting a link farm designed to redirect users to malicious content. The document body is heavily obfuscated and contains no readable text, further indicating a malicious intent to conceal its true purpose.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9978

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://ketchas.ru/uplcv?utm_term=best+indian+app+for+hide+photos+and+videos PDF link annotation
    • http://kfnmdg.com/upfolder/e/files/20210909082734.pdfIn PDF document text
    • https://sellos-mecanicos.com/wp-content/plugins/super-forms/uploads/php/files/36931f6a92eff332ae92e8b2eebca47f/47795328840.pdfIn PDF document text
    • https://dazhonghua1688.com/ckfinder/userfiles/files/japofij.pdfIn PDF document text
    • https://conexus-study-abroad-travel.com/ckfinder/userfiles/file/78132908157.pdfIn PDF document text
    • https://valubil.com/public/uploads/cms_file/cms_files/88287189220.pdfIn PDF document text
    • http://hotel-gerard-dalsace.com/upload/document/52348568327.pdfIn PDF document text
    • http://www.medical-psychology.gr/wp-content/plugins/formcraft/file-upload/server/content/files/1613caebb9863a---fomidegud.pdfIn PDF document text
    • https://gadd-asso.org/userfiles/file/11049910590.pdfIn PDF document text
    • https://flyags.com/editorResources/file///waxapupepidusegamasegobes.pdfIn PDF document text
    • http://kazuma.ru/ckfinder/userfiles/files/89627642077.pdfIn PDF document text
    • http://kleni.cz/userfiles/file/dotidudajurufo.pdfIn PDF document text
    • http://moneymaker-gold.de/files/kazubiluluro.pdfIn PDF document text
    • http://shyjjc.com/v15/Upload/file/2021951358321015.pdfIn PDF document text
    • http://claudiamelchior.it/images/file/xelanusugupumazawagiji.pdfIn PDF document text
    • http://www.naturhalles.fr/fckeditor/userfiles/file/rewerewodewilanal.pdfIn PDF document text
    • http://pantryscan.com/123cars/imagefck/file/pobuwatejamorem.pdfIn PDF document text
    • http://pytextiles.com/userfiles/file/70254378630.pdfIn PDF document text
    • http://postelezmasivu-brno.com/ckfinder/userfiles/files/falunikutevaxopave.pdfIn PDF document text
    • http://thriftstorewebsites.net/flash/thriftstorewebsites.net/file/56523430225.pdfIn PDF document text
    • http://pawsandtiaras.com/ckfinder/userfiles/files/77350993194.pdfIn PDF document text
    • http://www.megasaludips.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613e5aa413b6c---81637593562.pdfIn PDF document text
    • https://gaziemirkentkonseyi.com/upload/files/43890180070.pdfIn PDF document text
    • http://newabel.com/ckfinder/userfiles/files/vewanumifijesamumelupo.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_off0000b610.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB610 16452 bytes
SHA-256: e50e38b5d630dbbbadc0ada49138aa1d88d1c49bb15e8c4c92c12ab52509a97c
font_01_sfnt_off0000e014.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE014 10668 bytes
SHA-256: 56247dded38553655aac0af7569dcf6f2c969b595637032ec3ae48d1e91814c8
font_02_sfnt_off0000f882.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF882 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1