Malicious PDF — malware analysis report

Static analysis result for SHA-256 b4b87d0e510a8a3a…

MALICIOUS

PDF

101.5 KB Created: 2021-08-13 22:47:14 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: c41a4298c68275792e34b85e3c38275a SHA-1: 2d8712d9e4fca11eeb3c720341ef84f3d110d9ad SHA-256: b4b87d0e510a8a3a920f18987188395cdfa90b77ff77eb11d9c04b0ee096fe92
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The file is a PDF identified as malicious by ClamAV and an ML classifier, exhibiting characteristics of a link farm. It contains numerous URLs pointing to compromised CMS upload storage and disposable hosting, suggesting an attempt to redirect users to malicious content. The presence of external URI heuristics and the PDF_SEO_DISPOSABLE_LINK_FARM rule indicate a phishing or redirection scheme.

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://nodka.eu/ckeditor/ckfinder/userfiles/files/17072064740.pdf In PDF document text
    • https://www.davidwoodpersonnel.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606ca6d30d2d2---favifas.pdfIn PDF document text
    • http://engroupe.ca/aym_image/files/tuzezojabefutob.pdfIn PDF document text
    • http://www.sunargrup.com.tr/wp-content/plugins/super-forms/uploads/php/files/mane8ajhmnhp6gtrigmnftb0f2/15870756485.pdfIn PDF document text
    • https://nasikampung.info/contents//files/40014438402.pdfIn PDF document text
    • https://allegypttours.net/userfiles/files/detobivaribox.pdfIn PDF document text
    • https://stefandes.com/wp-content/plugins/formcraft/file-upload/server/content/files/16091b3b1ece17---sofikir.pdfIn PDF document text
    • http://imi.vc/upload/files/9327285939.pdfIn PDF document text
    • http://smartcookieacademy.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607fd43ed2002---zalul.pdfIn PDF document text
    • http://babywagen24.de/userfiles/file/49674667995.pdfIn PDF document text
    • https://livingcircles.ch/wp-content/plugins/formcraft/file-upload/server/content/files/160740c7add68d---falari.pdfIn PDF document text
    • http://europeanprofservices.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b554d9bb42c---8549123652.pdfIn PDF document text
    • https://humicdp.com/uploads/2021-07-01/images/files/kozubizafusivudok.pdfIn PDF document text
    • https://www.glasswindowequipment.com/wp-content/plugins/super-forms/uploads/php/files/333c48ab422d3ec5539c89110354ec8e/54544502394.pdfIn PDF document text
    • https://www.mixedclass.com.au/wp-content/plugins/super-forms/uploads/php/files/imihahgupid5iriqup26n96tti/tajolineli.pdfIn PDF document text
    • http://www.hangmandigital.com/files/file/delasabameveboxiluro.pdfIn PDF document text
    • http://localhomesales.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/16088992537c79---69286666290.pdfIn PDF document text
    • https://luminex.pl/upload/file/bigipevowuwo.pdfIn PDF document text
    • http://ipllaser.in/uploads/devuxa.pdfIn PDF document text
    • https://www.tangelo.no/wp-content/plugins/formcraft/file-upload/server/content/files/1608cb6af7ca5e---67464178261.pdfIn PDF document text
    • http://murphysbeads.com/clients/54316/File/86919132548.pdfIn PDF document text
    • http://indiebookoftheday.com/wp-content/plugins/formcraft/file-upload/server/content/files/160f4f973b206d---11858741265.pdfIn PDF document text
    • http://www.jobsincrete.gr/images/_user_na/file/4334405851.pdfIn PDF document text
    • https://betenenergy.com/sites/default/files/file/47322945387.pdfIn PDF document text
    • http://valleypainclinic.org/userfiles/file/7313395825.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/6naE_Nh8_CY/uplcv?utm_term=autentico+capitulo+1a+answersPDF 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_off00012588.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12588 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00013d9f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13D9F 10584 bytes
SHA-256: c2e97bde535c780fee6f60fa7ddca76059414f12dc4a2b1fec62a8a7fcabe296
font_02_sfnt_off0001560f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1560F 18912 bytes
SHA-256: 1ad0f66b79b6bafb9b933a13c6836e92cd411da7009725f44bb4e327664e8149