Malicious PDF — malware analysis report

Static analysis result for SHA-256 8459a241cf664acb…

MALICIOUS

PDF

81.5 KB Created: 2021-09-23 23:11:49 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 976cd75ce751e09614a79a964dbb444f SHA-1: 429d58735e90667ccfc940debfe4201086aa6b61 SHA-256: 8459a241cf664acbf975141cdb02f79bfb94c8c3296e7f50845d64be6a5c2851
156 Risk Score

Malware Insights

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

This PDF file was flagged by multiple heuristics as malicious, including a high-confidence ML classifier and ClamAV detection. It functions as a link farm, directing users to compromised WordPress upload storage and other disposable hosting sites. The presence of numerous external URIs and link farm indicators suggests an attempt to redirect users to malicious content, likely for phishing or malware distribution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://drafthe.ru/uplcv?utm_term=como+iniciar+o+android+em+modo+de+seguran%C3%A7a
    • https://minhkygroup.com/luutru/files/68773743843.pdf
    • http://sbstroy53.ru/img/files/24486438780.pdf
    • https://avis-medical.ma/wp-content/plugins/super-forms/uploads/php/files/4bb263f4d3cfe545575170f7cffbc57b/temapowasujipomufo.pdf
    • https://acethamessecurity.co.uk/wp-content/plugins/super-forms/uploads/php/files/16144cf79e3f8950696cc0a4eba35ed8/42211045501.pdf
    • https://kiofruits.com/admin/uploads/files/51076248486.pdf
    • http://spalovnachemolak.sk/userfiles/file/84231467299.pdf
    • http://akademibt.com/resimler/files/76368278466.pdf
    • http://galantemontagnana.it/ckfinder/userfiles/files/vapewitunomorikulu.pdf
    • https://kingbakerypans.com/userfiles/file/18065041466.pdf
    • https://feldmann-spedition.de/pics/userfiles/file/lesepezi.pdf
    • https://akonis.ch/userfiles/files/32512286032.pdf
    • https://cualuoihoanmy.com/uploads/userfiles/file/98459996997.pdf
    • http://www.johnknox.ch/wp-content/plugins/formcraft/file-upload/server/content/files/1613ac798e439a---kuzufedatujobubopovonomu.pdf
    • http://waterlootour.com/FileData/ckfinder/files/20210908_387499AC8B4CF327.pdf
    • http://tsradviseurs.nl/mailing/images/photo/file/60746758837.pdf
    • https://kuwaitpolyurethane.com/ckfinder/userfiles/files/59392384788.pdf
    • http://lambanghieuquangcaogiare.net/vietkiendo/upload/file/51658255636.pdf
    • https://rintrans.com/files/pigitewowuk.pdf
    • https://termofriz.rs/files/titewumafugorasun.pdf
    • https://0922.sproname.com/files/userfiles/files/99817688834.pdf
    • http://drxzhang.com/userfiles/file/2536708587.pdf
    • http://sanxuatbanthinghiem.org/app/webroot/uploads/files/fafizijula.pdf
    • https://die-elke.de/cms/elke_page_files/file/17616532761.pdf
    • 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_off0000d5ef.bin
deabac4279822c499db21c9993217cf5b8a951757d7e00c0cc2f836a66594d67
pdf-font-stream PDF embedded font (sfnt) at offset 0xD5EF 10900 bytes
font_01_sfnt_off0000ee9a.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xEE9A 16792 bytes
font_02_sfnt_off000106ac.bin
5a5137d8ce12bb34b579d03966738cee54e89b72e721e54acffaebdcad06fb0b
pdf-font-stream PDF embedded font (sfnt) at offset 0x106AC 19280 bytes