Malicious PDF — malware analysis report

Static analysis result for SHA-256 83c6a07a08e8e52f…

MALICIOUS

PDF

91.6 KB Created: 2021-06-29 17:00:35 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: 27bc81c82ec27eb87691bc97d0895b58 SHA-1: a14fe0396f53fc609aacb0c751ea9c138c55fb77 SHA-256: 83c6a07a08e8e52f7b132d8e16e475eb73f88858baa73daed10c53529b5e3c6e
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF was flagged by ClamAV as Pdf.Phishing.Trojan and ML classifiers indicated a high probability of maliciousness. It contains a link farm pointing to numerous compromised WordPress sites and other disposable hosting, suggesting a phishing or redirection scheme. While no scripts were explicitly extracted, the nature of the link farm and the detection as a Trojan implies it's designed to lead users to malicious content or exploit kits.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9876

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://kimtuong.vn/isc/public/files/fckupload/file/satanojiz.pdf In PDF document text
    • https://lsp.od.ua/wp-content/plugins/super-forms/uploads/php/files/9tq7ro3arv8vfv0210p8if7dj5/jepun.pdfIn PDF document text
    • https://www.alphaveneers.com/wp-content/plugins/super-forms/uploads/php/files/87f965145032758be7d235b3b9586cf6/xufufozokugemavinaz.pdfIn PDF document text
    • https://storage-in-motion.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609433fe2bffc---xegupilubog.pdfIn PDF document text
    • https://amesmedicalservices.com/wp-content/plugins/formcraft/file-upload/server/content/files/160723b78a5cfc---93621345405.pdfIn PDF document text
    • http://ridendo.cz/files/file/xuvizajepineg.pdfIn PDF document text
    • http://fulepmark.hu/nyebu/fulepmark/userfiles/file/38257509050.pdfIn PDF document text
    • https://www.qbuildsoftware.com/wp-content/plugins/super-forms/uploads/php/files/3f707c7fb885ab30bf05005fabd734d9/98176453414.pdfIn PDF document text
    • https://jfefood.com/wp-content/plugins/super-forms/uploads/php/files/1b4152f0a47b34e6174a6f9b15ec368e/fadiwurakabopolanaru.pdfIn PDF document text
    • https://relaxationplusmn.com/wp-content/plugins/super-forms/uploads/php/files/d20f8b7f721c867f94cf61793a025e78/60263921833.pdfIn PDF document text
    • https://sinarwaja.com/account/files/41275116993.pdfIn PDF document text
    • https://40parables.com/wp-content/plugins/super-forms/uploads/php/files/ba0cc476c9f42cde7b97b396de6abb30/sunutujadolitaditune.pdfIn PDF document text
    • https://www.saenger-ohg.de/wp-content/plugins/formcraft/file-upload/server/content/files/160d43ff94a0bf---9893981811.pdfIn PDF document text
    • https://binhruamuinanobac.com/wp-content/plugins/super-forms/uploads/php/files/p3g15n3fsmg4fjplc7mtrd8lfo/62626479708.pdfIn PDF document text
    • http://mujuerp.com/uploads/ckeditor/files/20210616031847.pdfIn PDF document text
    • https://www.budgetskemaet.dk/wp-content/plugins/formcraft/file-upload/server/content/files/1607acd7a33237---71170726799.pdfIn PDF document text
    • https://admonks.ru/wp-content/plugins/super-forms/uploads/php/files/af1380c97192f7426eb4fbdcc6999dab/nuxazunolifowigavupoxareg.pdfIn PDF document text
    • https://banghenails.com/upload/file/7915743204.pdfIn PDF document text
    • https://agilitynd.com/wp-content/plugins/super-forms/uploads/php/files/6faefebf53d3fdcce513ee5175388ce1/wusefadepafafuri.pdfIn PDF document text
    • http://smartcookieacademy.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a39fcc99820---77241591087.pdfIn PDF document text
    • https://www.varishastalari.com/wp-content/plugins/formcraft/file-upload/server/content/files/16078cdc0e4397---99949365370.pdfIn PDF document text
    • https://boldvision.tv/wp-content/plugins/formcraft/file-upload/server/content/files/160aa9ab904e1a---32764775463.pdfIn PDF document text
    • http://chaitraglaze.com/uploads/87381892804.pdfIn PDF document text
    • https://elbag.net/wp-content/plugins/super-forms/uploads/php/files/483113a2b425bed20bd062699fdd9e3f/mapekofedij.pdfIn PDF document text
    • http://yournamebadges.com/withyourdog/cms_uploads/file/88177976851.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/S30rS-6n6vg/uplcv?utm_term=mean+absolute+deviation+formula+in+excelPDF 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://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_off00010004.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10004 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00011816.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11816 19548 bytes
SHA-256: 6bc5730406917de69c22ad68a14d65fe6289f2470d270e34031ee71f523d272b
font_02_sfnt_off00014c1d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x14C1D 11040 bytes
SHA-256: b306b88f2418066eea2581015c46a4d1a68818ae4522e4be98a17c7a813b278e