Malicious PDF — malware analysis report

Static analysis result for SHA-256 c8017f867ed567c7…

MALICIOUS

PDF

86.7 KB Created: 2021-06-30 23:47:00 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: d0da9a6d68f2ef1a18e971e48dc9b980 SHA-1: 21ccad550ad36d4947c710ed5a9020943bb637c5 SHA-256: c8017f867ed567c74c7000bdd638352fdf5691e0c63216f925a74eb763bf8584
156 Risk Score

Malware Insights

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

The PDF file contains a large number of embedded URLs, many of which point to compromised WordPress sites. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or distributing further malware. The document body is heavily obfuscated and appears to be generated by wkhtmltopdf, suggesting it's not intended for direct user reading but rather as a container for malicious links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9952

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://bokseinstituttet.dk/wp-content/plugins/formcraft/file-upload/server/content/files/160bfd8c0be684---48445771702.pdf
    • https://maxim-catering.de/wp-content/plugins/super-forms/uploads/php/files/0ggmkpv2ah2afvrmndhvck1mft/wisofixawepekigulusuxined.pdf
    • https://wurstfargo.com/wp-content/plugins/super-forms/uploads/php/files/5f6fef4816d825bbcd5996625f093433/75245526326.pdf
    • http://www.segurosfacility.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1606d4e270224f---75283848757.pdf
    • http://rajskiewakacje.pl/userfiles/file/tekilemeredagapujenolep.pdf
    • https://childprotectionindia.com/lexcyberia/userfiles/files/45399915177.pdf
    • http://cnokorea.com/userfiles/file/viruw.pdf
    • http://www.1atlanticfunding.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b4bbd5774a3---jonotirefilaza.pdf
    • https://pasarantogeldua.com/contents//files/pewudovibesezi.pdf
    • https://beaufortbond.com/wp-content/plugins/super-forms/uploads/php/files/1bfac62381a94dd44b73edd53285a6de/lodilu.pdf
    • https://www.quatainvestimentos.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1607b0cf3408d9---peweladedidigejopuzifewon.pdf
    • https://webgirls-studio.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a761e265a07---zovoten.pdf
    • http://thm-holding.ru/wp-content/plugins/super-forms/uploads/php/files/e8ecbf5e40392bc9b2b1031ff69c971e/sosunadukafub.pdf
    • http://mediaworld.pro/ckfinder/userfiles/files/62185273302.pdf
    • https://specialbrands.gr/wp-content/plugins/super-forms/uploads/php/files/2e6f4493bfc9f709884f8db97fe80da1/nosapiwabawiwo.pdf
    • http://viaterrestre.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/16076937938124---kodilavonokurudug.pdf
    • http://informerfitness.com/wp-content/plugins/super-forms/uploads/php/files/3b7b19c88270cfabf8edd30216da3a6d/bijofuv.pdf
    • http://rana-international.com/userfiles/files/puronamopogigorigewuk.pdf
    • https://kodeac.com/wp-content/plugins/super-forms/uploads/php/files/b4u6vq5cgas36atuapmh2il9jd/47444966638.pdf
    • http://austria-ex.com/images/blog//file/8007152554.pdf
    • http://remontnoedelo.ru/wp-content/plugins/formcraft/file-upload/server/content/files/160905c50dcb5c---13842079841.pdf
    • https://bykevin.com/wp-content/plugins/super-forms/uploads/php/files/b162f15506bcb1741d852b7f4a06a9f3/99027960095.pdf
    • http://vegasoft.hr/wp-content/plugins/formcraft/file-upload/server/content/files/1606eee5b599a3---vigulifu.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/cv9VXjIrmdE/uplcv?utm_term=gamecube+game+id+list
    • 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_off0000f05d.bin
932aedabd90a10eac3c0a23ba0776480666cf37767c153942d38147a8e68daba
pdf-font-stream PDF embedded font (sfnt) at offset 0xF05D 10668 bytes
font_01_sfnt_off000108a3.bin
7227172c151879073057b8effbca94f74228157129672efbba6d54b56c016701
pdf-font-stream PDF embedded font (sfnt) at offset 0x108A3 17120 bytes
font_02_sfnt_off0001356f.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x1356F 16792 bytes