Malicious PDF — malware analysis report

Static analysis result for SHA-256 d71fd81e435d1b67…

MALICIOUS

PDF

80.4 KB Created: 2021-09-04 01:27:40 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: cb238a16a4714a5553136f3f1b0dc96f SHA-1: c682a7d84bf2d2c173904dea3f47f381c9d93967 SHA-256: d71fd81e435d1b67926dc245475e24b9586434dd1e1b40d9d5b4788de9763589
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains a link farm pointing to multiple compromised WordPress sites, a common technique for distributing malicious content or phishing lures. The ClamAV detection and ML classifier strongly indicate malicious intent. While no scripts were directly extracted, the PDF structure and embedded URLs suggest it's designed to redirect users to potentially harmful sites, likely as part of a phishing campaign or to download further malware.

Machine Learning

  • Nyx PDF Classifier malicious score 0.5825

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://www.fecomerciomg.org.br/wp-content/plugins/formcraft/file-upload/server/content/files/1608dc60d3c3c4---1841031044.pdf In PDF document text
    • https://www.frontierexim.com/wp-content/plugins/super-forms/uploads/php/files/2k30mg2gtk3gpa3kcac9i29n0c/55177383171.pdfIn PDF document text
    • http://am-assets.com/aom/magnolia/userfiles/file/guzokujeferotakunefatinu.pdfIn PDF document text
    • http://altadirezione-consulting.it/userfiles/files/xagumituzukubumarim.pdfIn PDF document text
    • http://www.playerclub.ro/wp-content/plugins/formcraft/file-upload/server/content/files/160b3fcf798459---92565370542.pdfIn PDF document text
    • http://tayles.com/uploaded/97541203787.pdfIn PDF document text
    • http://premiumresourcing.com/wp-content/plugins/formcraft/file-upload/server/content/files/16090307b951b3---27118109645.pdfIn PDF document text
    • http://vipavtoufa.ru/wp-content/plugins/super-forms/uploads/php/files/3bb433278b9fabe47caa04636c7e7728/5119525456.pdfIn PDF document text
    • http://xn--pr3b03lcdvwu9dpynqkc.com/DATA/file/20210725034841.pdfIn PDF document text
    • http://pokebarslo.com/uploads/files/23699874958.pdfIn PDF document text
    • http://greenplanetnepal.com/userfiles/file/finiwunidariwabijefa.pdfIn PDF document text
    • https://paklya.su/design/img/upload/file/fuxexakopaxed.pdfIn PDF document text
    • http://www.franklinwebdesign.com/wp-content/plugins/formcraft/file-upload/server/content/files/160838c0f7dc8f---8546453172.pdfIn PDF document text
    • http://africa-emergence2019.com/userfiles/file/gerinopoliror.pdfIn PDF document text
    • http://anneadamslaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/33569884515.pdfIn PDF document text
    • http://knx-shop.ru/admin/ckfinder/userfiles/files/55120083843.pdfIn PDF document text
    • http://22vek-omsk.ru/fck_editor_files/files/53018776511.pdfIn PDF document text
    • http://microcement.ua/userfiles/file/35303645752.pdfIn PDF document text
    • https://afriqueitnews.com/wp-content/plugins/super-forms/uploads/php/files/e0e8487a4e6c8ca9c7f7db7360d1e83a/82282609293.pdfIn PDF document text
    • https://bayardplaza.co.uk/wp-content/plugins/super-forms/uploads/php/files/ngpqp42m4o5eiden666fr3pnoh/32214954445.pdfIn PDF document text
    • http://ixtvs.de/_upload_bilder/_filemanager/file/xomupujabixizemanane.pdfIn PDF document text
    • http://cokhixnktientien.com/Images_upload/files/21537083054.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/S30rS-6n6vg/uplcv?utm_term=candidose+oropharyng%C3%A9e+pdfPDF link annotation
    • 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_off0000dae5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDAE5 10932 bytes
SHA-256: cc0aa4d098bb067a16645b2d1cdeea30995563015c42099351ae56ffa4c2868f
font_01_sfnt_off0000f3ad.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF3AD 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00010bbf.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10BBF 18928 bytes
SHA-256: c62ef77de8ae83da644bf458f256c251e6fbabd9253ef5f99f335a76f9ee80fd