Malicious PDF — malware analysis report

Static analysis result for SHA-256 26787d4523b4469b…

MALICIOUS

PDF

86.9 KB Created: 2021-07-26 20:58:30 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: 6f1b155d3d766b735a9d586a19fb3a07 SHA-1: a13ac3b9ee94294cf69516ef714bf58998d1d67b SHA-256: 26787d4523b4469b6feb5cd081a5aae4fef8da6c35785a290a77a12a77b7de02
96 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous links to external resources, many hosted on compromised WordPress sites, suggesting a link farm or redirection scheme. The ML classifier strongly indicates maliciousness. While no scripts were directly extracted, the PDF structure and embedded URLs point towards a phishing or malware distribution attempt, likely using a spearphishing attachment as the initial vector.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9976

Heuristics 5

  • 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 http://prodesign31.ru/wp-content/plugins/formcraft/file-upload/server/content/files/1607db8eba88bc---weginativigupu.pdf In PDF document text
    • https://www.sabiamente.es/wp-content/plugins/formcraft/file-upload/server/content/files/1609413b501136---90062311827.pdfIn PDF document text
    • http://ecologie-energie.com/userfiles/file/jenizovoxedenidibudexokep.pdfIn PDF document text
    • https://worldkelo.com/wp-content/plugins/super-forms/uploads/php/files/09b0a1d0316ace092e38ed81386fecee/wikamekelix.pdfIn PDF document text
    • http://bradleyhillsapartments.com/demo/uploads/contents/file/60347971703.pdfIn PDF document text
    • http://bubblesoflove.net/wp-content/plugins/formcraft/file-upload/server/content/files/1607550a90df99---nelone.pdfIn PDF document text
    • https://unitedcardsolutions.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bf0be2340c9---widepazax.pdfIn PDF document text
    • http://workcoop.org/fckeditor/userimages/file/20210611080757.pdfIn PDF document text
    • https://quaint-house.com/images/blog//file/13655610600.pdfIn PDF document text
    • http://benthanhfarm.com/images/uploads/files/saviso.pdfIn PDF document text
    • http://www.bestlifepolicy.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/1608b0ce0a7221---81041785211.pdfIn PDF document text
    • http://juha.be/_files/file/46733369324.pdfIn PDF document text
    • http://auxerretv.com/content/public/file/botuvutuwusep.pdfIn PDF document text
    • http://www.laterveer-biesenbeek.nl/ckfinder/userfiles/files/97897016160.pdfIn PDF document text
    • https://aryaayur.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b657c3f4202---javufowa.pdfIn PDF document text
    • http://abbwingslynnhaven.com/uploads/files/54870850389.pdfIn PDF document text
    • https://noukos.gr/wp-content/plugins/formcraft/file-upload/server/content/files/1609112a2afac4---nejoxelenunul.pdfIn PDF document text
    • http://www.dismaplant.com/ckfinder/userfiles/files/pipezaritexibenuxefulas.pdfIn PDF document text
    • http://lecieldesandes.fr/ckfinder/userfiles/files/78083336433.pdfIn PDF document text
    • http://suankaew.net/upload/userfile/files/78421557196.pdfIn PDF document text
    • https://fablab808.com/nbloom/fckuploads/file/69841746672.pdfIn PDF document text
    • https://pezenasenchantee.fr/userfiles/file/zedoxibujik.pdfIn PDF document text
    • https://tavio.ru/files/file/63815866821.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/DOqCt-cVA4I/uplcv?utm_term=second+law+of+thermodynamics+solved+problems+pdfPDF 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_off0000ed6e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xED6E 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00010585.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10585 11368 bytes
SHA-256: 1c05c76785edb7e588aaf8e4cd1b127262610659944d172700c4437cf6ae0afa
font_02_sfnt_off00011ff4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11FF4 17492 bytes
SHA-256: 2fc385d869b525adfae4b124f5ac4bfdcabe544b3da901a6fbd233140fc29eea