Malicious PDF — malware analysis report

Static analysis result for SHA-256 1897fb88acb6e3ba…

MALICIOUS

PDF

86.1 KB Created: 2021-07-03 00:06:18 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: f80e1127e216b2445a12a2802c8d0012 SHA-1: b9972348f142cad122d5b5b4f3769e8ab7700eb8 SHA-256: 1897fb88acb6e3baca067d65d9368260ea0b4e473a97cafae7ba4852ce4321bc
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF file identified as malicious by ML classifiers and ClamAV. It contains numerous links pointing to compromised WordPress sites, suggesting a link farm used to distribute further malicious content. The presence of PDF_SEO_DISPOSABLE_LINK_FARM and PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM heuristics indicates a deliberate effort to obscure the true destination of the links. While no scripts were directly extracted, the nature of the links and the overall detection suggest a phishing or malware distribution campaign.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9947

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://inchirierielicopter.ro/wp-content/plugins/formcraft/file-upload/server/content/files/1607e2ff4cf3ad---28593765176.pdf In PDF document text
    • http://www.maarsehoveniers.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1609c35c6ab2e8---kexexixixopavofimatis.pdfIn PDF document text
    • http://consade.com/userfiles/file/walasuwilip.pdfIn PDF document text
    • http://www.thaiboat.net/image/upload/File/79458923272.pdfIn PDF document text
    • http://plenar.hr/wp-content/plugins/formcraft/file-upload/server/content/files/16082962f82e05---semigo.pdfIn PDF document text
    • https://drivingschoolofnorthtexas.com/wp-content/plugins/formcraft/file-upload/server/content/files/160af95e28aa01---fedenemebanaladixudidu.pdfIn PDF document text
    • http://stitesattorney.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/75386193836.pdfIn PDF document text
    • https://www.baptistenhardenberg.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160ae7470bac4c---10016578701.pdfIn PDF document text
    • https://kingwaterpure.com/ckfinder/userfiles/files/lonelejozenizevak.pdfIn PDF document text
    • http://i-daa-wl.de/userfiles/8521953825.pdfIn PDF document text
    • http://xn----8sbpvg0afdbe.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/tak0beu3pk0v1o1as1or600t57/27449190709.pdfIn PDF document text
    • http://xn--90aoaidn.xn--p1ai/ckfinder/userfiles/files/47561627096.pdfIn PDF document text
    • https://www.escon.it/wp-content/plugins/super-forms/uploads/php/files/78a1ed2357fa2d8620c468eea6d2f9f4/61235962450.pdfIn PDF document text
    • https://renault-service.com/userfiles/29035835716.pdfIn PDF document text
    • http://qboardapp.com/wp-content/plugins/super-forms/uploads/php/files/b5f1bb10f2d5f63b9864c3d1fd1d8891/tevin.pdfIn PDF document text
    • https://klingende-zeder.de/wp-content/plugins/formcraft/file-upload/server/content/files/16086299604dfd---jotufa.pdfIn PDF document text
    • https://www.nordatec.com/wp-content/plugins/super-forms/uploads/php/files/8hhnt0sb40u6htf2lke74hjso9/31743033846.pdfIn PDF document text
    • https://www.finestkindcharter.com/wp-content/plugins/formcraft/file-upload/server/content/files/160acc70de8554---912385698.pdfIn PDF document text
    • http://www.euro-fly.eu/userfiles/files/babefugudexab.pdfIn PDF document text
    • http://madmojo.com/fckupload/file/58223660614.pdfIn PDF document text
    • http://farmaciafici.com/userfiles/files/8614697313.pdfIn PDF document text
    • https://www.beachesbrewing.com/wp-content/plugins/super-forms/uploads/php/files/428fe708c79d57980a86006f60989850/letaluvubebuwudapowamed.pdfIn PDF document text
    • https://regalcabs.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/160c978a17f255---13442186399.pdfIn PDF document text
    • http://ttlh.vn/storage/ckfinder/files/zewatebeladivajasijo.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/BkSY9tpko7c/uplcv?utm_term=book+of+riddles+pdfPDF 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://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_off0000ebe4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEBE4 18256 bytes
SHA-256: c3dca4a61c4c77df80f530f6c26b8ab9dac734de77d6e8154b1558652f8bc524
font_01_sfnt_off00011c19.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11C19 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00013430.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13430 10272 bytes
SHA-256: 7d30ce7651d5acce0873bed01762355e105db38ccc30ac5e866c352badcbea07