Malicious PDF — malware analysis report

Static analysis result for SHA-256 c381d783fb8a2d88…

MALICIOUS

PDF

80.8 KB Created: 2021-09-12 16:34:41 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: 7ba55b4e9f03b864a78ca7ecefdabc1f SHA-1: 8a8b018432b898c22793a46e9b98f240115a4cc2 SHA-256: c381d783fb8a2d888e8f5c789a04b8785b82fa4b5d5feb22de9b9382a86ccc6c
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF contains numerous embedded URLs, many of which point to compromised websites or are structured as link farms. The ClamAV detection and ML classifier strongly indicate malicious intent, likely phishing or malware delivery through these links. The presence of external URI heuristics and link farm indicators further supports this attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9968

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 https://harrisitalia.it/uploads/file/votobo.pdf In PDF document text
    • http://1-champagne.com/blog_images/blog_/file/30138154408.pdfIn PDF document text
    • https://cosplay-expo.it/ckfinder/userfiles/files/fosidakijizu.pdfIn PDF document text
    • https://bunian-co.com/other_files/File/wavusulonabujavalone.pdfIn PDF document text
    • http://ixtvs.de/_upload_bilder/_filemanager/file/82478146422.pdfIn PDF document text
    • https://comfortinnbarrie.com/phpsites/vertical_living/uploads/file/nasukivokugi.pdfIn PDF document text
    • http://ajtoablakcentrum.com/_user/file/84720207065.pdfIn PDF document text
    • http://pk-rowery.pl/user_pict/file/53249628297.pdfIn PDF document text
    • http://americandeliorder.com/uploads/files/xodamesadozubigupize.pdfIn PDF document text
    • https://dimensioninteractive.com/WYSIWYGImage/file/luzubazibaserilu.pdfIn PDF document text
    • http://faw-asia.com/image/upload/files/35871470967.pdfIn PDF document text
    • https://doellefjelde-mussemarked.dk/images/newsmail/file/waditugotuzavur.pdfIn PDF document text
    • http://villaturri.it/wp-content/plugins/formcraft/file-upload/server/content/files/161374129eab73---zizezoreladavudi.pdfIn PDF document text
    • https://gilbertems.com/videos/file/9652064735.pdfIn PDF document text
    • http://xn--b1agpbmdtf.xn--p1ai/upload/file/menoresuwubaki.pdfIn PDF document text
    • http://abhinavabhishad.org/userfiles/file/xetezidesebiwaruxox.pdfIn PDF document text
    • https://mastirz.com/userfiles/files/54755369274.pdfIn PDF document text
    • http://www.communityheroesproject.org/wp-content/plugins/formcraft/file-upload/server/content/files/161302e3b15edf---31940506941.pdfIn PDF document text
    • https://calienglish.com/ckfinder/images_store/files/midudixa.pdfIn PDF document text
    • https://www.tctnanotech.com/wp-content/plugins/super-forms/uploads/php/files/140089e5dbd740e4715947b134e837b1/35340772076.pdfIn PDF document text
    • http://yuhongzg.com/d/files/88168948357.pdfIn PDF document text
    • https://china-glass-mosaic.vegner.com/userfiles/files/20210907_082114.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/3CAf4wW3hvY/uplcv?utm_term=how+to+take+a+screenshot+in+mobilePDF 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_off0000d529.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD529 18408 bytes
SHA-256: 7ea3982a9762c4b3406fdcf35252380e95806044a56d1ebed04b481c0123b29e
font_01_sfnt_off000104fd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x104FD 10804 bytes
SHA-256: 1073600aa564bad595ecfdd2cb6d660df090d90750f83644b66c372b8268293b
font_02_sfnt_off00011db7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11DB7 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1