Malicious PDF — malware analysis report

Static analysis result for SHA-256 93d4d7865719d3ea…

MALICIOUS

PDF

81.0 KB Created: 2021-09-15 15:27:19 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: d33a459d4fff574f5d5b307050b45673 SHA-1: 9189b7ec5028d60e06498b1a3a46c57de3c47038 SHA-256: 93d4d7865719d3eaf6699d2b100a602ecc35f3e323c52e28b5032c9c743fe852
156 Risk Score

Malware Insights

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

The PDF file was flagged by ClamAV as Pdf.Phishing.Trojan and a machine learning classifier indicated a high probability of maliciousness. The document contains numerous embedded URLs, many pointing to compromised CMS uploads or disposable hosting, suggesting a link farm designed to redirect users to malicious sites. The primary attack pattern involves tricking users into visiting these external links, likely for phishing or malware delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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://synerhu.ru/uplcv?utm_term=dof+app+for+android PDF link annotation
    • https://www.gsccn.it/wp-content/plugins/formcraft/file-upload/server/content/files/1613f14614a46b---xasibalaguvajujag.pdfIn PDF document text
    • http://openendrep.com/userfiles/files/kezotet.pdfIn PDF document text
    • http://benetworkingpro.com/ckfinder/userfiles/files/62225200538.pdfIn PDF document text
    • https://www.hkfew.org.hk/ckfinder/userfiles/files/keruvinolu.pdfIn PDF document text
    • https://machnik.net/ckfinder/userfiles/files/jepum.pdfIn PDF document text
    • https://giorgiosantinelli.it/file/30612813612.pdfIn PDF document text
    • http://danangsculpture.com/uploads/image/files/tuzexi.pdfIn PDF document text
    • https://carmelocuritiba.com.br/ckfinder/userfiles/files/14614168634.pdfIn PDF document text
    • https://www.peltonfell.org.uk/ckfinder/userfiles/files/kiterixo.pdfIn PDF document text
    • https://cfi-registration.amyhalter.com/buzzboxgift/img/userfiles/files/68341359580.pdfIn PDF document text
    • http://gcsiva.com/files/userfiles/file/zaxipilenudiluvimurenod.pdfIn PDF document text
    • http://prplus4u.com/ckupload/files/2167888333.pdfIn PDF document text
    • http://stavo-bazar.cz/userfiles/file/bokiga.pdfIn PDF document text
    • https://www.americanapi.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614166ed84ae7---69619340024.pdfIn PDF document text
    • http://vipavtoufa.ru/wp-content/plugins/super-forms/uploads/php/files/58d7f413a9e7ab7d4e85120057efdc7f/bamimuwejoziga.pdfIn PDF document text
    • http://123dvere.sk/files/file/wudugosekelejuliwewujos.pdfIn PDF document text
    • http://veoguidecostarica.com/ci/userfiles/files/99167725403.pdfIn PDF document text
    • http://thehedgerowchronicles.com/ckfinder/userfiles/files/binadabepufif.pdfIn PDF document text
    • https://altstudio.be/app/webroot/uploads/file/69497116538.pdfIn PDF document text
    • https://fleuriste79.fr/ckfinder/userfiles/files/32178443149.pdfIn PDF document text
    • http://execdentalclinic.com/uploads/ckfinder/userfiles/files/sokak.pdfIn PDF document text
    • http://mygotour.com/FileData/ckfinder/files/20210906_4754C63758A3C005.pdfIn PDF document text
    • http://h-st.nl/bestanden/files/80660536363.pdfIn PDF document text
    • http://ty-int.com/files/files/fegezazivupalefalig.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_off0000d8ef.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD8EF 10048 bytes
SHA-256: 4b2afe94f545816242d44190d4927d0b13e107aa958a4b2c68ab26dfa57bc51c
font_01_sfnt_off0000ef3f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEF3F 17988 bytes
SHA-256: e481837acb98e6e2442f749919f2e7fe4240c836fce13cd25d9a2e22cda63ada
font_02_sfnt_off00011e33.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11E33 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1