Malicious PDF — malware analysis report

Static analysis result for SHA-256 cd7d44a330916d6e…

MALICIOUS

PDF

92.3 KB Created: 2021-06-28 01:41:20 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 7d34eeeae56b07fd8e9d1821bbc99cae SHA-1: 9992daf4c84ddf7bb6d6ff6de857b0f5063d73c8 SHA-256: cd7d44a330916d6e27f60f2bf29d079b239c99b776cb6fe3b0e9365151475a18
96 Risk Score

Malware Insights

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

The PDF contains a large number of embedded URLs, many of which point to compromised WordPress sites. The ML classifier strongly indicated maliciousness. The document body is heavily obfuscated and appears to be non-readable content, suggesting its primary purpose is not informational but rather to host these malicious links. No scripts were extracted, but the link farm behavior is indicative of SEO poisoning or a distribution point for further malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9937

Heuristics 5

  • 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://mko-yug.ru/wp-content/plugins/super-forms/uploads/php/files/6ee69298db0d2bb42d159d477a03c578/28066003183.pdf
    • http://cameralehiep.com/hinhanh_fckeditor/file/64710373251.pdf
    • https://emprenderem.cl/files/36956835983.pdf
    • http://pcmcpropertyblog.com/wp-content/plugins/super-forms/uploads/php/files/c9a2ee91d66cca6ccf0c2343702b27e6/92395220455.pdf
    • http://miamiwars.pl/wp-content/plugins/super-forms/uploads/php/files/4ea5956b07265e09159df8536f5665e7/kotumafonek.pdf
    • https://www.bouldersudbury.org/wp-content/plugins/formcraft/file-upload/server/content/files/160b35e4b5faab---77523036171.pdf
    • https://ajwatravel.com/wheelmarine/userfiles/file/54158078985.pdf
    • http://veivel.com/userfiles/file/nizusilabupib.pdf
    • https://brylka-kfz.de/wp-content/plugins/formcraft/file-upload/server/content/files/1607b74d8cf97d---megodivapowes.pdf
    • https://brusroom.com/wp-content/plugins/super-forms/uploads/php/files/66760cdcd3219d548abc14bdf5cc54d6/jemepinoraweruxirudesig.pdf
    • https://theshairpodcast.com/wp-content/plugins/super-forms/uploads/php/files/af65b3da160aca8ea5dcec1ab9a91ead/88188286543.pdf
    • http://www.sparkprototypes.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bf9e55ee0a6---89459935596.pdf
    • https://dolmalatrek.com/userfiles/file/57766431695.pdf
    • https://augsburger-dartliga.de/uploads/file/45378481248.pdf
    • https://sckprime.com/wp-content/plugins/super-forms/uploads/php/files/bf6f2c333360eaf1bd499627ec8624b8/zedevufu.pdf
    • http://nc2e.fr/wp-content/plugins/formcraft/file-upload/server/content/files/16096d85c0abe4---sekivawixinomuv.pdf
    • https://weinquartier.at/wp-content/plugins/super-forms/uploads/php/files/d75e8a3be91183cc0aa2ebad58156bda/19363605916.pdf
    • http://osheamaloneynylaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/93449365455.pdf
    • http://espacioschillout.es/images/admin/file/86361139776.pdf
    • https://alfa-clining.ru/wp-content/plugins/super-forms/uploads/php/files/e3ec559ffdf46cc95873413585990fb7/38480102192.pdf
    • https://alphaveneers.co.uk/wp-content/plugins/super-forms/uploads/php/files/0a1b2426f3e5efbff822b3c89bc48471/66232094570.pdf
    • http://www.northeastmarquees.com/wp-content/plugins/super-forms/uploads/php/files/5d8823d00df97f28530f8b66e73dc57b/zawufuwovezujuruvafi.pdf
    • https://ajitcoatings.com/uploads/juwamodulaloronelenagi.pdf
    • https://smarttactic.ro/wp-content/plugins/formcraft/file-upload/server/content/files/1609455f1a7566---645947708.pdf
    • https://polskieplytki.com/wp-content/plugins/super-forms/uploads/php/files/116d07759bd16fda52e3fa70a32125d6/64707439693.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/fzgW7-mxBc0/uplcv?utm_term=strong+nucleophiles+for+sn2
    • 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_off000101b4.bin
05bd7287b541f972d861eba80091d85eef8b423cf3ae1617ba8cdc63cadab15a
pdf-font-stream PDF embedded font (sfnt) at offset 0x101B4 10892 bytes
font_01_sfnt_off00011ada.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x11ADA 16792 bytes
font_02_sfnt_off000132ec.bin
cd9b3be628cd5f2a2167f816ff4b207baa03da46d98267b4cfda898919fa88d5
pdf-font-stream PDF embedded font (sfnt) at offset 0x132EC 18576 bytes