Malicious PDF — malware analysis report

Static analysis result for SHA-256 31da920b5af5d208…

MALICIOUS

PDF

81.3 KB Created: 2021-10-08 18:20:27 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-23
MD5: 36e7ad765f495b488b93b1579ab3eba5 SHA-1: 46bdbee45d631df4b2a979ea4e911ffbd9c8d3e8 SHA-256: 31da920b5af5d208478f41dc0c2a77bb09df014871a74f7c69b6bc526382f503
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 multiple compromised or disposable hosting sites. While no scripts were explicitly extracted, the PDF structure and embedded URLs suggest an attempt to redirect users to malicious content, likely for phishing or malware delivery.

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://voolabs.com/wp-content/plugins/formcraft/file-upload/server/content/files/1615363e5a756e---ditarulasapura.pdf In PDF document text
    • https://inmaabiladi.com/userfiles/files/68040279473.pdfIn PDF document text
    • http://marienoellebermond.com/img/uploaded/file/puxevepupup.pdfIn PDF document text
    • http://speednewslive24.com/assets/ckfinder/core/connector/php/uploads/files/38423873438.pdfIn PDF document text
    • http://matrixpaint.com/ckfinder/userfiles/files/jaxedekegakutudos.pdfIn PDF document text
    • http://geometrabottero.it/userfiles/files/78359588904.pdfIn PDF document text
    • https://banerjeetourspecial.in/ckfinder/userfiles/files/14710100611.pdfIn PDF document text
    • https://vmwarts.com/ecovic/file/zimoberiwibu.pdfIn PDF document text
    • https://edenestates.com/ckfinder/userfiles/files/jotelezanukobin.pdfIn PDF document text
    • https://krantiservice.com/ckfinder/userfiles/files/78636107984.pdfIn PDF document text
    • http://theemasternetworker.com/ckfinder/userfiles/files/pituwominuviwepa.pdfIn PDF document text
    • http://terapie-psi.ro/wp-content/plugins/formcraft/file-upload/server/content/files/1615b1d2ee3356---76414322901.pdfIn PDF document text
    • http://mientaytourist.com/uploads/files/34850832423.pdfIn PDF document text
    • https://thegmsbihta.in/userfiles/file/99815425636.pdfIn PDF document text
    • http://leruichem.com/upload/files/94506033838.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/1615a44038d349---80330452316.pdfIn PDF document text
    • https://perkunasstudio.com/uploads/files/202109112332371688.pdfIn PDF document text
    • https://www.puskinas.lt/ckfinder/userfiles/files/61286044789.pdfIn PDF document text
    • http://montoaneli.com/ckfinder/files/nowegonilotam.pdfIn PDF document text
    • http://electric-kernbichler.at/suxeduwegekisutometazi.pdfIn PDF document text
    • http://liceoadultos.juniorcollege.cl/userfiles/files/buzebivenoxituvijuvof.pdfIn PDF document text
    • http://stopasbestos.ca/wp-content/plugins/formcraft/file-upload/server/content/files/1614e44503f787---75415873971.pdfIn PDF document text
    • https://kirbas.com/img/uploaded/file/gotumeremonopaludem.pdfIn PDF document text
    • https://blueparadise.pl/userfiles/file/wogomojirigefufebume.pdfIn PDF document text
    • http://ymjgolf.com/file_media/file_image/file/pimatugukunewevafuba.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/GLLx1DTH0VQ/uplcv?utm_term=chester+zoo+jobsPDF 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_off0000da93.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDA93 17904 bytes
SHA-256: a9aeb72b8da96110ead7851fc4de8239d9dfb3fcd5d276147a9680a910e24fdb
font_01_sfnt_off000108ce.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x108CE 10164 bytes
SHA-256: f20f819732ea7006a97a28fc5343b9a38b3036d3c513ff0ec9569b33e427ab5b
font_02_sfnt_off00011fcb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11FCB 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1