Malicious PDF — malware analysis report

Static analysis result for SHA-256 4e85918a59bdf592…

MALICIOUS

PDF

80.2 KB Created: 2021-09-06 23:05:53 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: 2a5f5460e18c27ce8fdce64f94190070 SHA-1: 7d6c49b65addd29ff0c16ac75f5776aecbaf336b SHA-256: 4e85918a59bdf59284588e0cdc9ac4834186f7666b90480906871092e6e7ffff
156 Risk Score

Malware Insights

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

The PDF was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, directing users to multiple external websites, some hosted on compromised CMS uploads or disposable domains. The document body is heavily obfuscated and unreadable, suggesting it is not intended for human consumption but rather to facilitate the malicious link distribution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9960

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 http://career-id.org/ckfinder/userfiles/files/majiluninemonojik.pdf In PDF document text
    • https://local-atlas.ru/userfiles/files/74045703415.pdfIn PDF document text
    • http://rayanchem.com/d/files/81764749390.pdfIn PDF document text
    • https://guruamardaspublicschool.com/userfiles/files/9097068783.pdfIn PDF document text
    • http://kiavysocina.cz/UserFiles/File/bonuwikifitelabew.pdfIn PDF document text
    • http://anupbolivia.com/images/files/98332704493.pdfIn PDF document text
    • http://castanienfamily.com/clients/74558/File/50932754363.pdfIn PDF document text
    • http://aostavet.it/userfiles/files/vuxigurojazabudir.pdfIn PDF document text
    • https://k-newsletter.com/ckupload/files/53621124794.pdfIn PDF document text
    • https://kemxoi.vn/app/webroot/files/images/pages/files/99529446875.pdfIn PDF document text
    • http://donateagift.eu/userfiles/file/47143960444.pdfIn PDF document text
    • https://www.actionconstructionjax.com/wp-content/plugins/super-forms/uploads/php/files/c816de5df8bcf96262e6c9521e9d42b0/ligozimodekuzijeb.pdfIn PDF document text
    • http://bjhtdszdh.com/v15/Upload/file/20218795177961.pdfIn PDF document text
    • http://moristas.com/userfiles/files/poxer.pdfIn PDF document text
    • http://archimax.ch/dynamic-images/cms/file/20714963787.pdfIn PDF document text
    • https://www.yoursurveysurveyors.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/1609dc37d77d68---51121166039.pdfIn PDF document text
    • http://accronline.com/userfiles/file/soboti.pdfIn PDF document text
    • http://elitsatodorova.com/uploadfiles/file/3188234337.pdfIn PDF document text
    • http://villa-margherita.biz/userfiles/files/95178617852.pdfIn PDF document text
    • http://www.eflox.net/wp-content/plugins/formcraft/file-upload/server/content/files/160735332b2022---5976036231.pdfIn PDF document text
    • http://ekolojikweb.net/upld/userfiles/file/baruxekojorakorojaxer.pdfIn PDF document text
    • http://noithattamphuong.com/upload/files/duramiwove.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/PmAiG5ZyT-k/uplcv?utm_term=osmolaridad+urinaria+formula+pdfPDF link annotation
    • https://mediaget.com/userfiles/files/25976700928.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_off0000d4a1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD4A1 10552 bytes
SHA-256: 1e45f81bdd4767887b4dec728bdf4e3ae523a83b6fccb578faf6c5c8b6732895
font_01_sfnt_off0000ec8b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEC8B 17492 bytes
SHA-256: f7ec13752595b628ab3142dc2d98a33a98e390241a9782bded4ba9aa3787bbf4
font_02_sfnt_off000119c5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x119C5 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1