Malicious PDF — malware analysis report

Static analysis result for SHA-256 a954fb6f4cfa211d…

MALICIOUS

PDF

79.3 KB Created: 2021-06-20 09:36:30 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-02
MD5: 354ce66e38556900a6f7657bb62737eb SHA-1: 7fd6420ed1b4ca442ee2b6c12fe02aea1be250ca SHA-256: a954fb6f4cfa211da6a5ee1d222c02445b088bef367d77b4a0fa9de95e107bd7
156 Risk Score

Malware Insights

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

The PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It contains numerous links pointing to potentially compromised websites and disposable hosting, characteristic of a link farm used for phishing or malware distribution. The document body, though heavily obfuscated, contains metadata suggesting it was generated by wkhtmltopdf, a tool often used to create documents that mimic legitimate content to trick users.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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 http://bkbflooringusa.com/userfile/abbey/file/zobuxu.pdf In PDF document text
    • https://couvreur-hautdoubs.fr/internet_new/images_et_fichiers//file/54389947385.pdfIn PDF document text
    • https://www.spoton.pet/wp-content/plugins/super-forms/uploads/php/files/nhbp9ncscuf7dpeobahbl72ki6/vafagipupato.pdfIn PDF document text
    • http://www.associatedomains.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606e4e7fa45e9---zuzuxivazaxaresu.pdfIn PDF document text
    • http://nd-58.ru/wp-content/plugins/super-forms/uploads/php/files/11709df055535535239d0182d7d48fcd/zomoxiseku.pdfIn PDF document text
    • https://www.hotelamoha.it/wp-content/plugins/formcraft/file-upload/server/content/files/16097b4daa5cc7---58625656697.pdfIn PDF document text
    • http://www.immiflex.com/wp-content/plugins/formcraft/file-upload/server/content/files/16075e8cd4e46d---68863753506.pdfIn PDF document text
    • http://mobilni-kadernictvi.cz/files/file/gikinugudejowutifitalimu.pdfIn PDF document text
    • http://www.insurancedirectcanada.ca/wp-content/plugins/formcraft/file-upload/server/content/files/1606cce659730f---zasexaratawulipurujavetex.pdfIn PDF document text
    • http://altaprecision.com/userfiles/file/58651864687.pdfIn PDF document text
    • https://akdenizokullari.k12.tr/wp-content/plugins/super-forms/uploads/php/files/dtnoc80uscfnnnmp4l67khgpi9/52389069043.pdfIn PDF document text
    • https://www.stamfordtaxis.com/wp-content/plugins/super-forms/uploads/php/files/u88q3cpra1jso3vk60kncq69su/44721619664.pdfIn PDF document text
    • https://www.guestquesttravelmedia.com/wp-content/plugins/super-forms/uploads/php/files/df0rs1uajh6ldpp1r7i153e1aj/27299055564.pdfIn PDF document text
    • http://amfmeg.org/wp-content/plugins/formcraft/file-upload/server/content/files/1607815763ae04---wiwesuwida.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/YTWXjIUwRh0/uplcv?utm_term=watch+howl%2527s+moving+castle+123PDF 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://scripts.sil.org/OFLIn 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_off0000de5c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDE5C 5664 bytes
SHA-256: db66ddafcc2139e293ae96fb958f5cad6cc3fb73ef2a28247904a30f499923cd
font_01_sfnt_off0000f1b1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF1B1 11728 bytes
SHA-256: 3d640833cfb7e66c426baf478c9f0bc1d345985ed9cb1b9d9ef4e3f04fd429ae
font_02_sfnt_off000119ff.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x119FF 16068 bytes
SHA-256: 3b1167557c0500c78008053c404847a906c4d495ef15adec583fc97e76626070