Malicious PDF — malware analysis report

Static analysis result for SHA-256 a4c9b2eefa971fbf…

MALICIOUS

PDF

76.0 KB Created: 2021-07-07 08:51:12 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: 169a09d6bbb10f7d6493ddb67dc38158 SHA-1: 11ca877fd7974e4b330682c1ba62294db633f57b SHA-256: a4c9b2eefa971fbfb73a0d562508a374f54dd0427ca3431a172254e5409b51f7
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. It contains numerous links pointing to compromised or disposable domains, suggesting an attempt to redirect users to malicious content. The document body is heavily obfuscated and appears to be generated by wkhtmltopdf, lacking clear user-facing text but containing embedded URLs.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9840

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://eastmangroupllc.net/ckfinder/userfiles/files/mapibodileretonafegugu.pdf In PDF document text
    • http://discoveryenglish.org/wp-content/plugins/formcraft/file-upload/server/content/files/160850b5f4671d---10793788096.pdfIn PDF document text
    • http://www.uppld.org/wp-content/plugins/formcraft/file-upload/server/content/files/160707750e2bc9---46764099681.pdfIn PDF document text
    • http://www.shipsupply.co.mz/wp-content/plugins/formcraft/file-upload/server/content/files/1609c26ef46c91---83781879723.pdfIn PDF document text
    • http://eshop-kocicinadeje.cz/files/file/tekisumalomibanogivakimuj.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/160987445a5a13---galakebagol.pdfIn PDF document text
    • https://sitebyside.ru/wp-content/plugins/super-forms/uploads/php/files/edda5f0cf432a810d7d517806f864b68/gitefujizutaperopijejutuk.pdfIn PDF document text
    • http://rgn2u.com/userfiles/files/90691770753.pdfIn PDF document text
    • http://georgekoldun.com/var/upload/file/87506181355.pdfIn PDF document text
    • https://www.potterycommercials.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/1606e36cb72517---39975731030.pdfIn PDF document text
    • http://agrobud.net/uploaded/file/fuzexanajokida.pdfIn PDF document text
    • https://webgirls-studio.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606f2b200cc3f---20745059082.pdfIn PDF document text
    • http://ingmontagna.com/userfiles/files/16317982090.pdfIn PDF document text
    • http://www.zav-mito.si/wp-content/plugins/formcraft/file-upload/server/content/files/16085453de897b---budesaw.pdfIn PDF document text
    • http://bezpieczna-strefa.pl/wp-content/plugins/super-forms/uploads/php/files/1f5abcd2e5cc8135d26709bf72a454bc/22280482426.pdfIn PDF document text
    • http://tablica-nieruchomosci.pl/uploades/fckeditorfile/48633065307.pdfIn PDF document text
    • http://satbietthu.com/luutru/files/turixigoro.pdfIn PDF document text
    • https://aghs.in/ckfinder/userfiles/files/pemosagixegawowidufokoxib.pdfIn PDF document text
    • http://jagatjyotischool.org/jagatjyotischool/userfiles/file/pebevufukotadetebafo.pdfIn PDF document text
    • http://okuninka-biale.pl/userfiles/file/xelulixubopuzagogigupuvuj.pdfIn PDF document text
    • https://floridaholidayplanner.com/wp-content/plugins/super-forms/uploads/php/files/dd5e2abec3adc76a6a69c696e9e2ecd2/70117228907.pdfIn PDF document text
    • https://actioncoach.com.my/wp-content/plugins/formcraft/file-upload/server/content/files/16078393b63125---davari.pdfIn PDF document text
    • http://npxbyy.com/wang3_3_10_27/Upload/Upload/file/2021626191624477.pdfIn PDF document text
    • http://funkyspa.net/ckfinder/userfiles/files/51385614317.pdfIn PDF document text
    • https://dubigroup.com/admin/fckeditor/editor/filemanager/connectors/upload/file/15218888127.pdfIn PDF document text
    • http://hrjok.com/uploadfile/file/59420014117.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/1KS0DP0cxss/uplcv?utm_term=data+link+functionsPDF 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_off0000c870.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC870 10292 bytes
SHA-256: 685b4d44453d71f576001a161dff6c2f9bd0cca0104609830609970b77c57484
font_01_sfnt_off0000dfbc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDFBC 16452 bytes
SHA-256: 9a7602d82ee8a59b55696fd2f68d4997950598e9135905ceda5af9f341908248
font_02_sfnt_off00010aa7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10AA7 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1