Malicious PDF — malware analysis report

Static analysis result for SHA-256 b810c8d009ee4fb3…

MALICIOUS

PDF

67.4 KB Created: 2021-09-19 23:55:29 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: d526430a5f643c6fdcdd6ae61474158f SHA-1: 491a5589c22235e1f1f4d770f5cdb4aa1d65fe1f SHA-256: b810c8d009ee4fb384b66143bc3fc3d6e3e0ca9712e5f711881d958d10c157d9
116 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF is identified as a screenshot lure, containing numerous external links, many pointing to compromised CMS upload directories. The ML classifier strongly flagged this PDF as malicious. While no scripts were explicitly extracted, the presence of embedded URLs and the overall structure suggest it's designed to redirect users to malicious sites, likely for phishing or malware distribution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

Heuristics 6

  • Image-only document with action trigger (screenshot lure) medium PDF_IMAGE_LURE
    PDF has 1 image(s), only 0 text block(s), carries a click-outward action, and is only 67 KB — typical shape of a phishing lure where a full-page screenshot hides a clickable button that launches or submits to an attacker URL.
  • 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://garglob.ru/uplcv?utm_term=windows+xp+image+file+for+android PDF link annotation
    • http://www.sunaryem.com.tr/wp-content/plugins/super-forms/uploads/php/files/8sb4n6fsro1rl2g0blgskfpkj3/bepijidivosiro.pdfIn PDF document text
    • http://thanglong.vn-greenenergy.com/ckfinder/userfiles/files/22430303329.pdfIn PDF document text
    • http://yachtales.net/admin/userfiles/files/norenaxoxijap.pdfIn PDF document text
    • http://totalfinance.ca/wp-content/plugins/formcraft/file-upload/server/content/files/161458ee6481ac---16001104896.pdfIn PDF document text
    • http://pet.nfe.go.th/m_site/ckfinder/userfiles/files/wesajiduruj.pdfIn PDF document text
    • http://fonnepal.org/userfiles/file/52076455996.pdfIn PDF document text
    • http://debeight.net/UserFiles/File/dovadakafaguw.pdfIn PDF document text
    • http://eko-baby.ru/userfiles/file/51621788291.pdfIn PDF document text
    • http://sasnowosielski.com/ckfinder/userfiles/files/febijowavis.pdfIn PDF document text
    • http://nc2e.fr/wp-content/plugins/formcraft/file-upload/server/content/files/16141d69a82e67---dovuraj.pdfIn PDF document text
    • http://www.ashtralmedia.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614078f408ad8---dejufikakixowatu.pdfIn PDF document text
    • https://www.indee-r.fr/wp-content/plugins/super-forms/uploads/php/files/692b8441ae81f2ca7a7921e0673daf1e/nulotowudopuzazeli.pdfIn PDF document text
    • http://top-rubber.com/admin/fckeditor/editor/filemanager/connectors/upload/file/72912201731.pdfIn PDF document text
    • http://vincentianssjp.com/userfiles/file/sisetafafeluroxobakivup.pdfIn PDF document text
    • http://epodhajska.eu/UserFiles/File/46339236043.pdfIn PDF document text
    • http://dongzzang.com/userfiles/file///titefu.pdfIn PDF document text
    • http://rcsiprojectracker.com/userfiles/files/61677918447.pdfIn PDF document text
    • http://ineke-ott.nl/keramiek-beelden-imagesfile/12298585559.pdfIn PDF document text
    • http://clubselectionvoyages.net/images/file/wotufezakadeguxevegapofaj.pdfIn PDF document text
    • https://sapporopools.com/contents/files/zebotijapusivepitavawipi.pdfIn PDF document text
    • https://rt-totaalafbouw.nl/userfiles/file/62564930677.pdfIn PDF document text
    • 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_off0000ac47.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xAC47 13980 bytes
SHA-256: d9b27089f8ba95d8ba19c72b9752ed12c011d06c688437e2dad84cd2c19e7cd1
font_01_sfnt_off0000cef2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCEF2 10924 bytes
SHA-256: cfa666f9f33d8346c425760479b44673f1ce995dc5781079532c31b82b873c65
font_02_sfnt_off0000e80d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE80D 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1