Malicious PDF — malware analysis report

Static analysis result for SHA-256 98a738db53cb1add…

MALICIOUS

PDF

83.1 KB Created: 2021-09-01 11:47:01 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-01
MD5: 3ee96ec4e2e71513e9e20399fb7c36bd SHA-1: bb18607ba15cb31081250392dc00ce4ebca58a92 SHA-256: 98a738db53cb1add9d9e9d841ea28a3a540bea6391b9ddc850803bc378e1ab0d
96 Risk Score

Malware Insights

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

This PDF document was flagged as malicious by an ML classifier. The file embeds a large number of external links characteristic of an SEO link farm, many hosted on compromised CMS upload directories. Specific URLs and indicators for this sample are listed in the indicators section.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9983

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://chcial.ru/uplcv?utm_term=butter+bad+for+cholesterol PDF link annotation
    • http://dlmberatung.ch/userfiles/files/6486816233.pdfIn PDF document text
    • https://www.clubmanizales.com.co/wp-content/plugins/formcraft/file-upload/server/content/files/16094bb69521fc---90630992871.pdfIn PDF document text
    • http://quickfix-poland.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612ce7714065c---xikepewojawexaruxuke.pdfIn PDF document text
    • https://caror.hu/ckfinder/userfiles/files/luvuxodobepitetufilumes.pdfIn PDF document text
    • http://camberwelltaxi.com/survey/userfiles/files/pebaromazofapupobo.pdfIn PDF document text
    • http://www.veronicaneal.com/wp-content/plugins/formcraft/file-upload/server/content/files/1/160a1e3dc5cbf5---18608387115.pdfIn PDF document text
    • http://christmaslandint.com/userfiles/22408209780.pdfIn PDF document text
    • http://itineraire-consulting.com/ckfinder/userfiles/files/vorizaronabav.pdfIn PDF document text
    • http://rc-modeller.se/images/file///kesoxogivasem.pdfIn PDF document text
    • http://haiphongcontest.com/images/files/bogasawolexikaduzowana.pdfIn PDF document text
    • http://cementfeet.com/userfiles/file/fixodarokonizul.pdfIn PDF document text
    • http://jun-travel.com/userfiles/file/bazivoron.pdfIn PDF document text
    • http://komputerzagrosze.pl/userfiles/file/nojebovufinu.pdfIn PDF document text
    • https://www.rydalmereprestige.com.au/wp-content/plugins/super-forms/uploads/php/files/aqou56ofk9b3evji15ddnfvbpl/43241306846.pdfIn PDF document text
    • https://wronba.pl/uploads/wysiwyg/file/2179283399.pdfIn PDF document text
    • http://tw-sincere.com/upfiles/editor/files/jejikevu.pdfIn PDF document text
    • https://dodatnojamstvo.com/userfiles/file/vamenusufigajomeri.pdfIn PDF document text
    • http://drvision.org/wp-content/plugins/formcraft/file-upload/server/content/files/1609aff50a5b14---5674078305.pdfIn PDF document text
    • http://cropscipublisher.com/files/upfiles/file/48091848562.pdfIn PDF document text
    • http://csc0535.com/userfiles/file/20210708105436_3rkhm5.pdfIn PDF document text
    • https://gift-edu.ru/wp-content/plugins/super-forms/uploads/php/files/e72738bc6ed386b4b1f3df25769d824e/28068341410.pdfIn PDF document text
    • https://specialbrands.gr/wp-content/plugins/super-forms/uploads/php/files/a299029482b01215fc0cd865309712bd/4987200032.pdfIn PDF document text
    • http://amfmeg.org/wp-content/plugins/formcraft/file-upload/server/content/files/1609f48b7d83ab---fasijuxe.pdfIn PDF document text
    • http://jsdarvin.com/files/91292383825.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_off0000dca3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDCA3 18612 bytes
SHA-256: 67d67565b6b2ed3b532c43ed54b49723b14b64f06d4760be8a072af4b5fbfa0e
font_01_sfnt_off00010d8b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10D8B 10672 bytes
SHA-256: d1787e9aa036f5b1f3e5c118598142d866e7b36d5f290cf31b091f7b8066bc8b
font_02_sfnt_off0001262b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1262B 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1