Malicious PDF — malware analysis report

Static analysis result for SHA-256 5666c607b8c29b15…

MALICIOUS

PDF

87.4 KB Created: 2021-07-20 23:01:25 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 1155c532da9bed5ad164b92cadb883a3 SHA-1: ab68bef323b3f380fe464e0e828b0e3d90ad50d5 SHA-256: 5666c607b8c29b152cf79259dab5afcbc0d1b59da3f57dc1298790fd7b829662
96 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The PDF file contains a large number of external links, many pointing to compromised CMS upload storage and disposable hosting, indicating a link farm. The ML classifier also flagged this PDF as malicious. While no scripts were explicitly extracted, the nature of the link farm suggests it could be used to distribute further malicious content or for SEO manipulation.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9952

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 https://telenovella-bg.com/files/guxujezuxisadok.pdf In PDF document text
    • http://2016.letnifestiwal.pl/ckfinder/userfiles/files/88044539222.pdfIn PDF document text
    • https://ludifrance.fr/userfiles/file/dagopokuzubabodesonebe.pdfIn PDF document text
    • http://www.mvdisposal.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607aa06a6044b---gudepubuwiwasaxukobarudo.pdfIn PDF document text
    • http://maslag.eu/userfiles/file/45721617175.pdfIn PDF document text
    • https://razvozka24.ru/wp-content/plugins/super-forms/uploads/php/files/d9d2e69ac5855dbbbd5bbd3e445d92f4/zatuzez.pdfIn PDF document text
    • http://vegasoft.hr/wp-content/plugins/formcraft/file-upload/server/content/files/16076097fe6481---59326393615.pdfIn PDF document text
    • https://dolaodong.com/userfiles/file/juvejagaxumek.pdfIn PDF document text
    • http://penzionnakrizankach.cz/ckfinder/userfiles/files/favafudawetubimegikix.pdfIn PDF document text
    • http://zamokugrofa.sk/admin/fckeditor/file/70594688298.pdfIn PDF document text
    • http://airsoft1.ro/files/file/85956041133.pdfIn PDF document text
    • http://www.ellisrasbetonwerke.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/160958c52353e9---50456210953.pdfIn PDF document text
    • http://xn--b1ahhafccpgkb2bxo.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/92c1a2baf9ea5812e73dc9f8567a79c7/raxawovose.pdfIn PDF document text
    • https://www.jscorporation.co.in/wp-content/plugins/formcraft/file-upload/server/content/files/160a662e2c4e92---pageviniluwozewulujaso.pdfIn PDF document text
    • http://accurateverdicts.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607f3a1206b21---45757713428.pdfIn PDF document text
    • https://123natura.com/stockages/files/webetojijidanas.pdfIn PDF document text
    • https://southernlightingsource.com/wp-content/plugins/super-forms/uploads/php/files/f452439cac02b5719bd7d889809009fb/jebinazimomit.pdfIn PDF document text
    • https://samiznojmo.cz/wp-content/plugins/super-forms/uploads/php/files/593acaa79f34ff2e11e2ca24cdb205a8/10231424251.pdfIn PDF document text
    • http://veterina-hrib.cz/user-uploads/files/79297972954.pdfIn PDF document text
    • http://vickerycarpet.com/uploads/images//files/63532603530.pdfIn PDF document text
    • http://sl-light.ru/design/img/upload/file/gositemexobeno.pdfIn PDF document text
    • http://cathugo.de/res/wysiwyg/file/26364008204.pdfIn PDF document text
    • https://bbpartner.cz/userfiles/file/42822142699.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/1KS0DP0cxss/uplcv?utm_term=black+hole+in+our+solar+systemPDF 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_off0000f2ee.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF2EE 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00010b05.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10B05 10856 bytes
SHA-256: 07d2bbce3c26438f3dad88bad5691aa56a384a1202cdff03d9ec6908ae3ba68b
font_02_sfnt_off000123fb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x123FB 16412 bytes
SHA-256: 2acf7f6a2fabeb75748dfbadcd376e4f2f13a6b9354eb445140d580f512d880e