Malicious PDF — malware analysis report

Static analysis result for SHA-256 27cefdfa3981a237…

MALICIOUS

PDF

101.2 KB Created: 2021-09-07 04:06:15 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: 0e383018ac76fa089bc1680a9ec22665 SHA-1: ffc5a6067b74584f603436be5b646a7b027c7797 SHA-256: 27cefdfa3981a2377df520eb216449b0d506fd19285ef47bb5f3aa1df9cc151e
96 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains a large number of embedded URLs, many of which point to compromised WordPress sites or disposable hosting, indicating a link farm. The ML classifier strongly flagged this PDF as malicious. While no scripts were explicitly extracted, the nature of the URLs suggests a potential for redirecting users to malicious sites or phishing pages, possibly leveraging embedded JavaScript for obfuscation or redirection.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9938

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://krisoc.ru/uplcv?utm_term=automatic+gear+shifting+mechanism+pdf PDF link annotation
    • http://farmina.ru/uploads/files/80723318850.pdfIn PDF document text
    • https://vokalensemble-vocembalo.ch/userfiles/file/bumazesitanajatogazojuk.pdfIn PDF document text
    • http://intechsol.kz/wp-content/plugins/formcraft/file-upload/server/content/files/1609063f18131d---38291668266.pdfIn PDF document text
    • http://kaushalacademy.org/ckfinder/userfiles/files/roxiwikefedufubul.pdfIn PDF document text
    • http://timavoshipsupply.it/userfiles/file/85283784676.pdfIn PDF document text
    • http://www.adatechotomasyon.net/wp-content/plugins/formcraft/file-upload/server/content/files/16091b5b12a0ce---27047618023.pdfIn PDF document text
    • http://zulaikhatextile.com/userfiles/files/35554484765.pdfIn PDF document text
    • https://nacionalequipamentos.com/ckeditor/uploads/files/20495324651.pdfIn PDF document text
    • https://maconlux.lu/userfiles/files/wuligatekowur.pdfIn PDF document text
    • http://www.reenactmentmarket.eu/images/wyswig_images/file/lexosopedixawupolejuzib.pdfIn PDF document text
    • http://lnv-cnc.com/userfiles/file/fulozofikota.pdfIn PDF document text
    • http://proxima-design.cz/files/file/xamozimibosemusafofoged.pdfIn PDF document text
    • http://xfswchem.com/upload/files/guvadijiwowumotit.pdfIn PDF document text
    • https://atcotourismtravel.com/userfiles/file/58228110971.pdfIn PDF document text
    • https://chasehr.in/userfiles/file/79379880149.pdfIn PDF document text
    • https://mediabandit.com/wp-content/plugins/formcraft/file-upload/server/content/files/160aec0b799e58---zuluj.pdfIn PDF document text
    • https://plagij.at/ckfinder/userfiles/files/dovolosubisurinoxub.pdfIn PDF document text
    • http://studiobardinisrl.com/userfiles/files/44758809174.pdfIn PDF document text
    • https://engravestone.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608650bde6c8a---21129559330.pdfIn PDF document text
    • https://balance-global.com/wp-content/plugins/super-forms/uploads/php/files/97u7dpe2opjia8bofg71cqt5ps/48298286278.pdfIn PDF document text
    • https://socialchangefactory.org/wp-content/plugins/super-forms/uploads/php/files/a1bbab6075c5840f97d7d67cab735a8a/bulifejapamameje.pdfIn PDF document text
    • http://nusamulticentralestari.com/Uploads/userfiles/files/3996434529.pdfIn PDF document text
    • http://shortguycentral.com/ck_uploads/files/33934959308.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_off0001241f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1241F 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00013c36.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13C36 11100 bytes
SHA-256: 7ba28525bf172f4df1ea0af58f5f42750f59dfe47c6d2c66bb2b9ebc328d02d3
font_02_sfnt_off000155c4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x155C4 18984 bytes
SHA-256: c8157c9bbce0086b023f4844883819ed50679d16bfb995eb89152e53ca47517b