Malicious PDF — malware analysis report

Static analysis result for SHA-256 a8cb901177d6fa68…

MALICIOUS

PDF

87.0 KB Created: 2021-07-16 17:03:12 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-13
MD5: ca3c16b2e97dcf2aff581b392607d6bc SHA-1: 217d9d24d2b0c69f074e9fc9473a7aed225d45fd SHA-256: a8cb901177d6fa685e1880e05cd2c3147a96fdec22e9af7abbb8bb4b61f3d49f
156 Risk Score

Malware Insights

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

The PDF file contains numerous external links, many of which point to compromised websites or disposable hosting, indicating a link farm designed to distribute malicious content. The ClamAV detection and ML classifier strongly suggest malicious intent, likely phishing or malware distribution through these links. No scripts were extracted, and the document body was unreadable, so the primary attack vector is the embedded URLs.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9946

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://rmissio.pl/wp-content/plugins/formcraft/file-upload/server/content/files/160a7f3f0ec320---9467082011.pdf In PDF document text
    • https://cerquilho.sp.gov.br/public/admin/globalarq/uploads/files/wigesutodi.pdfIn PDF document text
    • http://nuestratierrapremios.com/campannas/file/43579154133.pdfIn PDF document text
    • https://www.harasportcenter.com/wp-content/plugins/super-forms/uploads/php/files/4f7f8nn3r3bk1ambbrbjh9s0l3/45032149956.pdfIn PDF document text
    • http://goldartline.ua/userfiles/file/nujuwesin.pdfIn PDF document text
    • http://perchegouet.com/ckfinder/userfiles/files/pegibedodisigavezewuju.pdfIn PDF document text
    • http://www.rebranded.tv/wp-content/plugins/formcraft/file-upload/server/content/files/160c4ce11906b4---56176212348.pdfIn PDF document text
    • http://chiengthai.com/file_media/file_image/file/1815255480.pdfIn PDF document text
    • https://atx-stroy.ru/wp-content/plugins/super-forms/uploads/php/files/208988c4c256d4c6766cdb8bea7185ae/41659033657.pdfIn PDF document text
    • http://backupcenters.com/userfiles/file/89618592095.pdfIn PDF document text
    • https://adbadog.com/wp-content/plugins/super-forms/uploads/php/files/00e35b987b31f92e26828e32a34d0e86/gixofovul.pdfIn PDF document text
    • https://canadianrelocation.net/wp-content/plugins/formcraft/file-upload/server/content/files/1608c661fca177---44349005941.pdfIn PDF document text
    • https://cihangirhotel.com/upload/ckfinder/files/52319411188.pdfIn PDF document text
    • http://szalkasszorutacskok.hu/app/webroot/files/content/files/45768694107.pdfIn PDF document text
    • https://amkboiler.com/wp-content/plugins/super-forms/uploads/php/files/f2uo3r5jatngtu97929nk27417/91939302665.pdfIn PDF document text
    • https://www.actionconstructionjax.com/wp-content/plugins/super-forms/uploads/php/files/8faab72a71b165b4b9f73d19e612ca1a/kagamelubuzurux.pdfIn PDF document text
    • https://www.andimoda.com/wp-content/plugins/super-forms/uploads/php/files/a4fb2ab9bbaca53e347809df4c3c30e9/dibawagalinupoverebojiwo.pdfIn PDF document text
    • https://regalcabs.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/160755e8fa940f---54100966361.pdfIn PDF document text
    • http://kochamsushi.pl/UserFiles/file/34819309617.pdfIn PDF document text
    • http://www.ashtralmedia.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a365311e4e4---dixepinunemigid.pdfIn PDF document text
    • https://www.amiunaorchestra.ro/wp-content/plugins/formcraft/file-upload/server/content/files/1606e783b53425---82429565791.pdfIn PDF document text
    • http://www.sunarsurdurulebilir.com/wp-content/plugins/super-forms/uploads/php/files/jniqm5a86s3ljhrkf77l8dv7c7/1186671525.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/Om9ozkHLxGw/uplcv?utm_term=how+to+build+a+cannon+in+minecraftPDF 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_off0000da5d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDA5D 17268 bytes
SHA-256: c62ebd9e1a18d5fda6d40780ac9a05d04e3e99e44a296081ca8e1e6a151d355e
font_01_sfnt_off00010793.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10793 16336 bytes
SHA-256: adf38969d40f501586e0caf93d33991e243baeeecfe575c4831cdbf64b7044fa
font_02_sfnt_off00011d95.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11D95 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_03_sfnt_off000135ac.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x135AC 10788 bytes
SHA-256: f31282e7ef2f8c4c379af44a3cdd28cd43c06061f76ec8cacf7c49e64f7356ed