Malicious PDF — malware analysis report

Static analysis result for SHA-256 6e4daeb319db24d5…

MALICIOUS

PDF

76.1 KB Created: 2021-09-11 02:18:49 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: ed6b0e1b93a26f640f2e0b45440058b2 SHA-1: c5642918a4250fd5b77ae5c91658fee48fa13029 SHA-256: 6e4daeb319db24d57e5b4cbeb9c7156fba95b097ef17aea2d500507dab399057
104 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF file flagged by ML classifiers as malicious. It contains a large number of external URIs, many of which point to PDF files hosted on various domains, suggesting a link farm designed to distribute further malicious content. The presence of embedded JavaScript, though not explicitly detailed, further supports the potential for malicious activity within the PDF.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9963

Heuristics 6

  • 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://spiregene.com/image/files/20210910_023045.pdf In PDF document text
    • http://wsm.hk/images/files/47040857691.pdfIn PDF document text
    • https://guijek.com/userfiles/file/joxizovodopi.pdfIn PDF document text
    • http://atenngo.com/admin/sites/site/documents/tegetifikovotagigil.pdfIn PDF document text
    • https://nationalshield-uae.com/userfiles/files/fisarajisewe.pdfIn PDF document text
    • http://www.laterveer-biesenbeek.nl/ckfinder/userfiles/files/pesedifajikumux.pdfIn PDF document text
    • http://baheth24cars.com/ckfinder/userfiles/files/xadetuvamuzixixesebiba.pdfIn PDF document text
    • http://www.webtony.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/16135b161de524---156921707.pdfIn PDF document text
    • http://swiftnb.com/ckfinder/userfiles/files/42805184233.pdfIn PDF document text
    • https://smarttactic.ro/wp-content/plugins/formcraft/file-upload/server/content/files/16139e8b21c9ff---vijenimorixiwewel.pdfIn PDF document text
    • http://phyllisrubensteinlaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/fowarum.pdfIn PDF document text
    • http://cardealer-space.com/js/upload/files/33160169484.pdfIn PDF document text
    • http://narnivet.com/userfiles/files/zokufaz.pdfIn PDF document text
    • https://nepalmicrofinancesummit.org/userfiles/files/bokisasezowitepeputubota.pdfIn PDF document text
    • https://lostsoulsmemorialnj.org/wp-content/plugins/super-forms/uploads/php/files/36ac9917c5f04c731361fc953ec54bdf/gajulofaveru.pdfIn PDF document text
    • http://handsonmontessoripk.com/userfiles/files/80850246199.pdfIn PDF document text
    • http://exosportsante.fr/ckfinder/userfiles/files/sokeno.pdfIn PDF document text
    • https://idfusionllc.com/wp-content/plugins/super-forms/uploads/php/files/7ddbce82ba221ddb29b7f16b1d91bf59/50523483142.pdfIn PDF document text
    • http://qcfloor.com/userfiles/file/gajodowovukedobexedaniked.pdfIn PDF document text
    • https://caraudioshop.ro/mm/file/zimoxabiworivezekabazila.pdfIn PDF document text
    • https://teater77.nl/userfiles/file/xeresuru.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/1xuhb7AK25c/uplcv?utm_term=pic+stitch+apkPDF link annotation
    • http://www.thaiticketmajor.com/static/imgUpload/files/66809295618.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_off0000c55b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC55B 18240 bytes
SHA-256: ad1bb8d52290f77ace70ed3352bd0c83977e05f3f2e401ecf5a550c88b7b31b3
font_01_sfnt_off0000f4b5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF4B5 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00010ccc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10CCC 10060 bytes
SHA-256: c08f55efe678b7cf6498dc59015ed1896473dc5d5e91805b90846db0061d526e