Malicious PDF — malware analysis report

Static analysis result for SHA-256 8f3cd8054d930b3f…

MALICIOUS

PDF

81.8 KB Created: 2021-09-14 13:16:12 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: 70d9fa6c44b4e68a15ebbdebf58ec6b3 SHA-1: f73a1fb48ef8b7ca43e1fb85ab605c943a98a700 SHA-256: 8f3cd8054d930b3f96079e4c491c9654a4cff228e30bc5981400a1145b7e83e1
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many of which point to compromised websites or are part of a link farm strategy. The ML classifier and ClamAV detection strongly indicate malicious intent, likely phishing or malware distribution through these links. 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 0.9966

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 http://tbm-mova.by/images_from_html_editor/file/74417247319.pdf In PDF document text
    • http://sbs-group.co/userfiles/files/98052752122.pdfIn PDF document text
    • https://srsatta.com/ckfinder/userfiles/files/dasogijen.pdfIn PDF document text
    • http://teenmag.cz/userfiles/file/83916804187.pdfIn PDF document text
    • http://www.jobsincrete.gr/images/_user_na/file/28063092393.pdfIn PDF document text
    • http://winkeleninzundert.nl/uploadimages/files/12335786790.pdfIn PDF document text
    • http://actlogistic.vn/upload/editor/files/59331364986.pdfIn PDF document text
    • https://get-insurance.in/ckfinder/userfiles/files/giritadurevugapubajilif.pdfIn PDF document text
    • http://visualpaint.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612ef9ca476b0---zilanevikuwozewup.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/161362b0c58f05---wavoxaxitofezol.pdfIn PDF document text
    • http://thaoduocquyhiem.com/userfiles/image/file/xekuvamevakixudejarimav.pdfIn PDF document text
    • http://massimosusto.eu/userfiles/files/wajidorefixuk.pdfIn PDF document text
    • https://magerp.org/upload/files/19013153144.pdfIn PDF document text
    • https://www.kiakaha.gr/wp-content/plugins/super-forms/uploads/php/files/lvq28muf0hckb1le0s9vp3io0k/vikewuf.pdfIn PDF document text
    • http://tsradviseurs.nl/mailing/images/photo/file/jakufodotudasonudo.pdfIn PDF document text
    • http://henskeschildersbedrijf.nl/upload/35771991370.pdfIn PDF document text
    • http://artetendasud.it/userfiles/files/nutakesomudilosejatirazar.pdfIn PDF document text
    • https://amkboiler.com/wp-content/plugins/super-forms/uploads/php/files/37sul1hvgtvnjm9v5lgtronv3l/53032925139.pdfIn PDF document text
    • http://www.swaving-stalinrichting.nl/ckfinder/userfiles/files/kamawuxaf.pdfIn PDF document text
    • http://sherwoodchambergolf.org/ckfinder/userfiles/files/57374942927.pdfIn PDF document text
    • https://rubfila.in/files/file/sakodofoliv.pdfIn PDF document text
    • https://cruiseship.cruises/wp-content/plugins/super-forms/uploads/php/files/6estp830b0tc3ee5poprsi8q58/vunik.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/ngfLrbzwjls/uplcv?utm_term=upper+intermediate+grammar+exercises+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 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000c0ae.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC0AE 16128 bytes
SHA-256: e086d997b6ee3c3fe48f8fdf49e8854b9e9bef9c53b5c2c5f26bba4f2b277426
font_01_sfnt_off0000d60c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD60C 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000ee1e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEE1E 19604 bytes
SHA-256: 3a44325939ee86655e34ed75647d949533c902ba413bae7ce7089182594b9487
font_03_sfnt_off0001200c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1200C 10904 bytes
SHA-256: fddf5526e5f32798c0bef6d680cb3b3355e1f253a3f0cb8aa501462c41770d47

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