Malicious PDF — malware analysis report

Static analysis result for SHA-256 ab8a8bc439c1ce11…

MALICIOUS

PDF

81.5 KB Created: 2021-07-02 21:22:11 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-14
MD5: b267953e799f68b68c483d8d9d6a9b78 SHA-1: af8220b5e604187065e07b86799513fd81c935ce SHA-256: ab8a8bc439c1ce1150d5a5d737bae37483433082e456b3646a5119b345a09605
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF containing embedded JavaScript, which is often used to exploit vulnerabilities or redirect users to malicious sites. Heuristics indicate the PDF acts as a link farm, with many links pointing to compromised CMS uploads and disposable hosting, suggesting an attempt to manipulate search engine results or distribute further malware. The ML classifier and ClamAV detection strongly indicate malicious intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9955

Heuristics 7

  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://rkmaster.ru/uploads/files/55349572823.pdf In PDF document text
    • http://www.amedna.com/userfiles/files/86639824516.pdfIn PDF document text
    • https://aprilboya.com/userfiles/file/bimosis.pdfIn PDF document text
    • http://anandtouristcorporation.com/uploads/gifubode.pdfIn PDF document text
    • https://tfnd.org/wp-content/plugins/super-forms/uploads/php/files/61fc59c979b1bc2483cda14864217a5f/75802913779.pdfIn PDF document text
    • https://jamiatulbanat.in/wp-content/plugins/formcraft/file-upload/server/content/files/160772af0d338d---81135433777.pdfIn PDF document text
    • https://camile.vn/wp-content/plugins/super-forms/uploads/php/files/kvo6h77v8q3vp03t69vm76rpoj/44667957791.pdfIn PDF document text
    • https://standardpromotion.com/images/upload/userfiles/files/82561471453.pdfIn PDF document text
    • https://asiatravel.kg/wp-content/plugins/super-forms/uploads/php/files/c4eb47db3d9cc0e9250522fcd5f0f0bd/78222079844.pdfIn PDF document text
    • https://by-express.com/upfiles/editor/files/9357756572.pdfIn PDF document text
    • https://www.vbclighting.com/wp-content/plugins/super-forms/uploads/php/files/83cf9575c70c7a6ca8121b75432bdf83/49275490969.pdfIn PDF document text
    • http://burningspearmarketplace.com/js/ckfinder/userfiles/files/24449043883.pdfIn PDF document text
    • https://trichynext.com/wp-content/plugins/super-forms/uploads/php/files/4df8d5b4c2fe87d8f4052454b570a13f/9633780571.pdfIn PDF document text
    • http://altaprecision.com/userfiles/file/ribozila.pdfIn PDF document text
    • http://akkoryazilim.com/userfiles/file/riwux.pdfIn PDF document text
    • http://illinoislivestock.org/userfiles/file/woronexewuvawita.pdfIn PDF document text
    • https://radmangroup-ye.com/rgfiles/file/90782539259.pdfIn PDF document text
    • https://area34.info/wp-content/plugins/super-forms/uploads/php/files/3nbam56pcjk9ioltb7qbndr7g2/33570935313.pdfIn PDF document text
    • http://studiotecnicodavico.eu/userfiles/files/4776913053.pdfIn PDF document text
    • https://impariant-club.ru/wp-content/plugins/super-forms/uploads/php/files/9fc77c06a5eaa7d72c7430148a91d989/pojexadumuni.pdfIn PDF document text
    • https://ises.ca/phpsites/vertical_living/uploads/file/rexona.pdfIn PDF document text
    • https://chrmglobal.com/userfiles/file/72328091879.pdfIn PDF document text
    • https://turbooto.vn/upload/files/10894315832.pdfIn PDF document text
    • https://www.aceitedeoliva.com/wp-content/plugins/super-forms/uploads/php/files/198df2b51f7621d4f8d20efc07acd456/38015831158.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/Om9ozkHLxGw/uplcv?utm_term=dragon+ball+complete+series+torrentPDF 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_off0000d68b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD68B 10856 bytes
SHA-256: e8a81bc7072886531b64e603053814cbc19c9c706010d9a143399729a093b486
font_01_sfnt_off0000ef5d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEF5D 19416 bytes
SHA-256: e71b150e3ec43a7ef03a5d7553f68b0b07c4c7c47e27c37fdb4c290643eaefec
font_02_sfnt_off000120af.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x120AF 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1