Malicious PDF — malware analysis report

Static analysis result for SHA-256 3dfb4b5e78399a5a…

MALICIOUS

PDF

81.2 KB Created: 2021-09-03 01:10:07 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 35b8916e6c846cc4aed17f69566c9b39 SHA-1: bdc3d64a2fa94d36e65bef8b1ddc5a1cdea75f9c SHA-256: 3dfb4b5e78399a5a716ad07c942ddd4fd28262cd6209841f2e57ab6f49f43494
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The PDF contains embedded JavaScript and a large number of external URIs, many of which point to compromised CMS upload directories or are part of a link farm. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or malware distribution by redirecting users through these links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

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 https://catamma.ru/uplcv?utm_term=vlsi+physical+design+books+pdf
    • https://iiml-pgpsm.in/ckfinder/uploads/userfiles/files/dusixub.pdf
    • https://www.vigo.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/160b059dd82486---wopesozenumiwovot.pdf
    • http://imhome-listings.com/userfiles/files/xubuvizuj.pdf
    • http://emailreceptionist.net/userfiles/file/70700212520.pdf
    • http://www.loockuniformes.com.br/home/wp-content/plugins/formcraft/file-upload/server/content/files/16120d95bb73d8---91244966128.pdf
    • http://www.asslar.de/downloads/47290499838.pdf
    • https://t4g.nasscomfoundation.org/wp-content/plugins/super-forms/uploads/php/files/sentf6qo71552c34ebjir612f3/14027271463.pdf
    • http://ri-rm.ru/userfiles/file/jiximiri.pdf
    • https://senzedigicraft.com/wp-content/plugins/super-forms/uploads/php/files/d11a59b7facb74154e24bb2cdeec5636/tomadububativuvuvifesogub.pdf
    • https://xn--80aanugxqi.xn--p1ai/admin/ckfinder/userfiles/files/xowiwemax.pdf
    • http://fobas.cz/userfiles/file/12316313900.pdf
    • https://schmitz.cz/res/file/5312483103.pdf
    • https://coachtourbusrental.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612390a1914d3---kefujubopedowakazujapez.pdf
    • https://greenvalleykerala.com/ckfinder/userfiles/files/bedufobami.pdf
    • http://precedent.by/_newsite/images_from_html_editor/file/dubugewu.pdf
    • http://highendschmiede.de/highendfiles/file/jupodijox.pdf
    • http://socialbomjesus.org.br/wp-content/plugins/formcraft/file-upload/server/content/files/1606c7d8ce9055---rubemozomewo.pdf
    • https://www.dentaltaxpros.com/wp-content/plugins/super-forms/uploads/php/files/ac070442bb7a488820cc6b2abe4a1bea/70354408215.pdf
    • https://parklanehotel.asia/userfiles/file/12422423039.pdf
    • http://www.pratikchoudhury.com/fckimages/file/riluweruwasug.pdf
    • http://burningspearmarketplace.com/js/ckfinder/userfiles/files/28366066894.pdf
    • http://ozdesignhouse.com/app/webroot/uploads/files/bugumukexu.pdf
    • http://www.startservis.sk/novy/ckfinder/userfiles/files/dupusufazi.pdf
    • http://homelife-superstars.com/image/files/97398221595.pdf
    • https://gamletaarnhuset.no/wp-content/plugins/formcraft/file-upload/server/content/files/1609b6d776527c---paranotusexinisokuzegu.pdf
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000dab0.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xDAB0 16792 bytes
font_01_sfnt_off0000f2c2.bin
3e42b6be2a1e190c7e251c43ed80a204a8c04cc7f8f2194542f1a35d6e4f19a3
pdf-font-stream PDF embedded font (sfnt) at offset 0xF2C2 16828 bytes
font_02_sfnt_off00011dda.bin
6d72fc7ca28e44a114e22e6b0a74786ac6a234843ac948074f678ec96937c1b1
pdf-font-stream PDF embedded font (sfnt) at offset 0x11DDA 11016 bytes