Malicious PDF — malware analysis report

Static analysis result for SHA-256 122031c64e97f871…

MALICIOUS

PDF

91.8 KB Created: 2021-09-16 10:08:05 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: 34961cd33b9fefdea01cafbc01d0b984 SHA-1: 09b22eba117277b4962de56dc31b226d1a8c2b46 SHA-256: 122031c64e97f871c04366d4d46a9f6b84bd5d1e188303a29f1e3aed2a3b89de
156 Risk Score

Malware Insights

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

The PDF file was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, with numerous URLs pointing to compromised CMS uploads and disposable hosting. The document body is heavily obfuscated and appears to be generated by wkhtmltopdf, suggesting it's not intended for direct user reading but rather to host links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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 http://erpsamik.com/ckfinder/userfiles/files/wubozejubesabifokuk.pdf In PDF document text
    • http://movitecnic.fr/ressource/site-image/files/35792636381.pdfIn PDF document text
    • https://rhdplumbing.com/wp-content/plugins/super-forms/uploads/php/files/5d40e2724088fb6a4e166aa341bc0c19/mevawugosufibizet.pdfIn PDF document text
    • http://umrllc.com/userfiles/files/81531989146.pdfIn PDF document text
    • https://rt-totaalafbouw.nl/userfiles/file/bibimitotajugawimagimaro.pdfIn PDF document text
    • https://rrvchefs.com/wp-content/plugins/super-forms/uploads/php/files/45d7d9c78ed163e6db77fa49fe15e69a/38558874309.pdfIn PDF document text
    • http://daiichihr.com/uploads/news_file/89857713198.pdfIn PDF document text
    • http://www.advokat.com/app/webroot/img/fck/file/39727990681.pdfIn PDF document text
    • https://stealthwindow.tw/uploads/files/202109071253206182.pdfIn PDF document text
    • http://qboardapp.com/wp-content/plugins/super-forms/uploads/php/files/36eccceb876b3309758d386cc532b50f/64943237273.pdfIn PDF document text
    • http://lecieldesandes.fr/ckfinder/userfiles/files/79865624141.pdfIn PDF document text
    • http://ferramentabelleggia.it/public/file/16908302544.pdfIn PDF document text
    • https://michaels-limo.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613f53449c0bf---zedon.pdfIn PDF document text
    • https://www.limratechnologies.net/wp-content/plugins/formcraft/file-upload/server/content/files/16140be003d54a---11139149577.pdfIn PDF document text
    • http://cathugo-yachts.de/res/wysiwyg/file/nukufurezaxokesolus.pdfIn PDF document text
    • http://touristclub.in/userfiles/file/296707850.pdfIn PDF document text
    • https://mut-zur-veraenderung-hambuch.de/userfiles/file/vivatejimesurobesoz.pdfIn PDF document text
    • http://atletika-pardubice.cz/files/file/64461359084.pdfIn PDF document text
    • https://minhvuongthuphap.com/upload/ck/files/lamabi.pdfIn PDF document text
    • http://nm-union.ru/ckfinder/userfiles/files/peniboxogosifabafabapu.pdfIn PDF document text
    • http://falconartistmanagement.com/ckfinder/userfiles/files/25003414672.pdfIn PDF document text
    • http://ourgans.org/userfiles/files/wumonamufonewoja.pdfIn PDF document text
    • https://irish-setter-zucht.info/ckfinder/userfiles/files/judopikediruna.pdfIn PDF document text
    • https://www.sgestrecho.es/wp-content/plugins/formcraft/file-upload/server/content/files/1613e3d3e314b3---dogoxoditadifamewed.pdfIn PDF document text
    • https://badrivishal.com/media/19805791114.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/YTWXjIUwRh0/uplcv?utm_term=head+soccer+frivPDF 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_off00010609.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10609 17168 bytes
SHA-256: 4fd496bd16f7aec43c30a03ee3aade4eb7120870056278b385b5b9f2cf950817
font_01_sfnt_off0001326a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1326A 10276 bytes
SHA-256: 3c488407544811bc030d575e5235f0cdc432ba8954f51544b9ea923905714644
font_02_sfnt_off0001499c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1499C 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1