Malicious PDF — malware analysis report

Static analysis result for SHA-256 958c071fef8878ad…

MALICIOUS

PDF

79.8 KB Created: 2021-09-13 12:56:53 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-24
MD5: eb7575c79544476b957f3a1a63ed3c23 SHA-1: a962b1d351bf6161013157153d49c387a2749d2c SHA-256: 958c071fef8878adc0e72b051abe12c7494fa9d1723cee9fbd984e76ac2a99c8
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample was detected as malicious by ClamAV and ML classifiers, indicating a high likelihood of malicious intent. The PDF contains numerous embedded URLs pointing to a link farm hosted on various domains, with a heuristic specifically flagging it as a 'PDF_SEO_DISPOSABLE_LINK_FARM'. While no scripts were explicitly extracted, the nature of the embedded URLs suggests a phishing or scam lure, likely intended to redirect users to malicious content or further stages of an attack. The authoring application 'wkhtmltopdf' is noted, but does not directly indicate malicious behavior.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9968

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://hunde-katzen.at/soubory/24133331264.pdf In PDF document text
    • http://asude.istanbul/ck_images/files/lanufupawilemamazepitiga.pdfIn PDF document text
    • https://ntc-container.com/upload/files/wojofibopob.pdfIn PDF document text
    • http://designklasse.de/ckfinder/userfiles/files/jupojanu.pdfIn PDF document text
    • https://pecsikult.hu/files/file/7550791546.pdfIn PDF document text
    • http://www.mariabeckmann.com/fotos/uploads/files/15658003527.pdfIn PDF document text
    • http://yilip.net/userData/board/file/9765528041.pdfIn PDF document text
    • http://bharatdarshan.net/rgroup/ckfinder/userfiles/files/748380372.pdfIn PDF document text
    • https://swaarm.de/app/webroot/upload/files/dirukenozikageguluvaxowu.pdfIn PDF document text
    • http://ps-chiptuning.hu/userfiles/files/kozufokoda.pdfIn PDF document text
    • http://abbeytraining.net/userfiles/file/ropakasomosi.pdfIn PDF document text
    • https://millinerandassoc.com/files/file/sexakadavumukidasonari.pdfIn PDF document text
    • http://ctm.it/userfiles/file/kirixodagiropudibura.pdfIn PDF document text
    • http://angelofthewinds.org/ckfinder/userfiles/files/vagepenebijafagujaker.pdfIn PDF document text
    • http://joesservicecenternj.com/userfiles/files/61462106440.pdfIn PDF document text
    • http://www.lbf-cosmetics.com/website/wp-content/plugins/formcraft/file-upload/server/content/files/1613ed88c51ce8---nosidebazofibeletawu.pdfIn PDF document text
    • https://kcss.hu/korosi/userfiles/file/dojawobakinifez.pdfIn PDF document text
    • https://www.thecandystoresudbury.com/wp-content/plugins/super-forms/uploads/php/files/buuo5ngsin7lbua5bd12a9a64v/nelalupasokipalotiruzivef.pdfIn PDF document text
    • https://www.sudoku-cool.com/ckfinder/userfiles/files/gefezaxuxoferenakirux.pdfIn PDF document text
    • http://www.expertnutritionadvisor.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613378231e433---88605296842.pdfIn PDF document text
    • http://newmob.it/userfiles/files/2721815750.pdfIn PDF document text
    • http://aaas.handyfriendship.com/upload/files/laposexugonemitupa.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/FevRqgeaUVY/uplcv?utm_term=spark+chat+androidPDF 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_off0000d419.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD419 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000ec2b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEC2B 18080 bytes
SHA-256: 541757ba41840252c6651e154ebcdb4138a6207c610cdc7094dc6a2d8bbddf7d
font_02_sfnt_off00011aae.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11AAE 10432 bytes
SHA-256: 47fd15c8e49a530d5d6c2f06d6da00089aeba65f23aceab1a35725fbf4d42794