Malicious PDF — malware analysis report

Static analysis result for SHA-256 cbdebd72bb5c5cb8…

MALICIOUS

PDF

72.3 KB Created: 2021-09-03 05:01:57 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: 5d41927ea03aa06fdf5a4a90a3734125 SHA-1: 93aae772d2f57b931b624de67e3ece007d36faa4 SHA-256: cbdebd72bb5c5cb8967919f344f93d43aa668cc1ef8d08b0a88f4c0e3cc0f2eb
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF document contains a large number of embedded URLs, many of which point to compromised CMS upload directories or disposable hosting. The ML classifier and ClamAV detection strongly indicate malicious intent, likely phishing or malware delivery through these links. The document body is heavily obfuscated and unreadable, providing no direct content clues.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9915

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://altonika.pro/files/fck/file/lofijokuzulem.pdf In PDF document text
    • http://jrmhandling.nl/upload/file/veluwi.pdfIn PDF document text
    • http://stl-hk.net/userfiles/viwapupa.pdfIn PDF document text
    • http://thessalonikiflights.com/files/files/mitelosudibufe.pdfIn PDF document text
    • https://levin-dent.ru/wp-content/plugins/super-forms/uploads/php/files/9cc48a782cbf0f15d5b292ba2630fac2/5338420633.pdfIn PDF document text
    • http://math-talk.kr/wp-content/plugins/super-forms/uploads/php/files/sbi0sgldmda030deja8d21ldbe/17241191295.pdfIn PDF document text
    • https://malimbe.africa/wp-content/plugins/super-forms/uploads/php/files/9f0db0a9720884c4ed90902c61733ff5/wunomenuvokitole.pdfIn PDF document text
    • http://mintaialuminum.com/d/files/74522523588.pdfIn PDF document text
    • http://hainescentreasia.com/images/file/gelubezeruxanogoluge.pdfIn PDF document text
    • http://kortennis.co.kr/B/ck/ckfinder/userfiles/files/36242096170.pdfIn PDF document text
    • https://walnutcreekguide.com/wysiwygfiles/file/xujis.pdfIn PDF document text
    • http://eis-pieschel.de/UserFiles/File/37929976857.pdfIn PDF document text
    • http://archimax.ch/dynamic-images/cms/file/43517533462.pdfIn PDF document text
    • http://remontnoedelo.ru/wp-content/plugins/formcraft/file-upload/server/content/files/1608c7b08d45e9---6950060421.pdfIn PDF document text
    • https://bonpetsupply.com/wp-content/plugins/formcraft/file-upload/server/content/files/16074ba0633f24---leziwavusopewivunitixa.pdfIn PDF document text
    • http://doggystylzgrooming.com/admin/photos/file/jojuga.pdfIn PDF document text
    • https://mebelpozakazu.ru/wp-content/plugins/super-forms/uploads/php/files/7d823824d256485466b41be8e4da52a4/sunexitoxaxozakosujela.pdfIn PDF document text
    • https://lasvegasrebath.com/wp-content/plugins/super-forms/uploads/php/files/48bf1c65cf44cbb1dc5f8e9dc7c5eaea/64313411312.pdfIn PDF document text
    • http://www.x454.com/wp-content/plugins/super-forms/uploads/php/files/daim68b9hgj4k40i4o3iu7hfh0/48307762855.pdfIn PDF document text
    • http://chatyzvule.cz/uploads/bodimufedeguruxaxuj.pdfIn PDF document text
    • http://limoride.net/gallery/file/numuli.pdfIn PDF document text
    • https://dijitalsanat.link/upload/files/3413520780.pdfIn PDF document text
    • http://rusiuojigalvoji.lt/wp-content/plugins/formcraft/file-upload/server/content/files/16108e305aa96a---xazivizadazovalajuxuzinut.pdfIn PDF document text
    • https://saikekanglun.com/filespath/files/20210903095450.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/161299f1414797---10315780731.pdfIn PDF document text
    • http://www.asejnrtigers.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/160c4a3c4724ef---94364289597.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/zMnd8XtcwSM/uplcv?utm_term=diffraction+techniques+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_off0000bbea.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBBEA 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000d401.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD401 10920 bytes
SHA-256: fa28d172e60d11183aef23c9034ac1bd0d6bd1e4b0c4ad3a27d2dd727b710de6
font_02_sfnt_off0000ed04.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xED04 15136 bytes
SHA-256: 7e2245431f07caf308daf37ad31aa4707ad2725581bcb1952a58471c2ffb7372