Malicious PDF — malware analysis report

Static analysis result for SHA-256 4b916d6d242b84ae…

MALICIOUS

PDF

105.8 KB Created: 2021-09-06 08:16:12 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: f944fe25a8e1a8f52f171a08a856c915 SHA-1: a3b69caea2e515ee1dd71d9d1d10ac57d90e9015 SHA-256: 4b916d6d242b84aea2ced68cf54c850e8434ed2c6abd2611ee74f93cde7e86c5
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF file flagged by ML classifiers and ClamAV as malicious. It contains numerous external links, many pointing to domains associated with compromised CMS uploads or disposable hosting, suggesting a link farm or phishing lure. The presence of embedded URLs and the nature of the heuristics indicate an attempt to redirect users to malicious content, likely for SEO poisoning or to facilitate further attacks.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9966

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://ketchas.ru/uplcv?utm_term=droit+constitutionnel+jurisprudentiel+pdf PDF link annotation
    • http://grafichesirio.com/userfiles/files/16972646135.pdfIn PDF document text
    • http://baschin-heizung.com/meineBilderAlbertGrundschule/file/dimetejodejowedenor.pdfIn PDF document text
    • https://skyzoan.com/cake/beta/userfiles/file/77991325686.pdfIn PDF document text
    • http://falerisztika.hu/tmp/93067424644.pdfIn PDF document text
    • https://wavesmaroochydore.com/wp-content/plugins/super-forms/uploads/php/files/65vs7ftn0603g721nrt8vare7h/79018873818.pdfIn PDF document text
    • https://2acontractor.it/images/file/luwimifelumaxawuteko.pdfIn PDF document text
    • http://terezmisszio.eu/files/file/sajigugipej.pdfIn PDF document text
    • http://blatt-gruen.ch/files/16283716024.pdfIn PDF document text
    • https://ever-progress.com/upload/files/wepaputazetatib.pdfIn PDF document text
    • https://baxsporthorses.com/userfiles/file/51194759037.pdfIn PDF document text
    • http://webursitet.org/Files/file/fodupasifaxev.pdfIn PDF document text
    • https://alignerco.com/wp-content/plugins/super-forms/uploads/php/files/c5cafd1892b5b1b57ce09daad5d25aa5/tibabuturigonularomile.pdfIn PDF document text
    • https://bahceneryaman.net/public/content-images/files/19726131858.pdfIn PDF document text
    • https://avgdesign.com/userfiles/file/95636787331.pdfIn PDF document text
    • https://mercedesmazo.es/wp-content/plugins/formcraft/file-upload/server/content/files/16075bc0787186---64025814568.pdfIn PDF document text
    • http://rayocazar.com/images/elfinder-1.1/files/file/72682117836.pdfIn PDF document text
    • https://sasalidayanisma.org/uploads/file/8856077098.pdfIn PDF document text
    • https://www.davidwoodpersonnel.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ee307dd3fea---11266625985.pdfIn PDF document text
    • http://for-rent-leuven.com/wp-content/plugins/formcraft/file-upload/server/content/files/161054dad8808b---pobewimuvabub.pdfIn PDF document text
    • http://ubest.ru/images/file/42919889515.pdfIn PDF document text
    • http://geniuschulatutor.com/userfiles/files/14462847834.pdfIn PDF document text
    • http://18554080.com/userfiles/file/zobuw.pdfIn PDF document text
    • https://tenfci.org/userfiles/file/xekopag.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_off00013084.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13084 10680 bytes
SHA-256: 0623024feec02346c48f1cfc5eba8c1e6a6b3cb4bc73fa4d35657b6ea59561af
font_01_sfnt_off0001490d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1490D 21808 bytes
SHA-256: 10444b8b0ca4a7e5b6ba351d9a74fccc830f114ac99e184ed0e74ac1c83cc780
font_02_sfnt_off00017f69.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x17F69 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1