Malicious PDF — malware analysis report

Static analysis result for SHA-256 a8ceb7851c33d9eb…

MALICIOUS

PDF

144.0 KB Created: 2021-09-06 17:55:54 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: fd277ace6e6361204077a1583ee76dfd SHA-1: 883e5eb32b9fe4f4aea38d7ea8c5b3fac44ef354 SHA-256: a8ceb7851c33d9eb56256ca83d5d221a96724422885779d09b83f0bf40893b1e
154 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The sample was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It contains numerous links pointing to compromised WordPress sites, suggesting it's part of a link farm used to distribute further malicious content or conduct phishing. The PDF structure and link farm indicate a tactic to redirect users to potentially harmful external resources.

Machine Learning

  • Nyx PDF Classifier malicious score 0.8846

Heuristics 5

  • 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
  • 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://medok18.ru/wp-content/plugins/super-forms/uploads/php/files/4329accf36a10e881258cfc4acf52591/8817116788.pdf In PDF document text
    • https://frontiersneurophotonics.org/wp-content/plugins/formcraft/file-upload/server/content/files/1/160993ac682456---kakutefupejebubeniranonox.pdfIn PDF document text
    • http://www.christinemartin.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/16085cb7bcca2b---30582789625.pdfIn PDF document text
    • http://www.christinemartin.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/1607ce23cdc610---totimakoduvizizutunokavug.pdfIn PDF document text
    • https://truck-diagnostic.ru/wp-content/plugins/super-forms/uploads/php/files/2387e63453418609981e71a93f070b48/63513706324.pdfIn PDF document text
    • https://www.psalighting.com/wp-content/plugins/super-forms/uploads/php/files/8eb67b5c0dd3d13057c55c78f9f13e5e/nivavefisudi.pdfIn PDF document text
    • http://www.lightingandhvacexpo.com/wp-content/plugins/super-forms/uploads/php/files/dd412ee80d895abd94f786eb592d34f5/zepopavulewelol.pdfIn PDF document text
    • http://claudiodauelsberg.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1609ae62d1d0c0---zulixilutepal.pdfIn PDF document text
    • https://patriot.ch/wp-content/plugins/super-forms/uploads/php/files/oninlq5a5rvpgg9katn29k8bek/33819536704.pdfIn PDF document text
    • http://kenzoum.org/home/integrity/public_html/ckfinder/userfiles/files/92122402291.pdfIn PDF document text
    • http://hajni.pl/userfiles/file/49442045031.pdfIn PDF document text
    • http://wrhs1976.com/clients/0/08/080801f2a31a95d446b71e9836a5425d/File/najen.pdfIn PDF document text
    • https://northwestconvention.cz/data/files/pafuga.pdfIn PDF document text
    • https://cruiseship.cruises/wp-content/plugins/super-forms/uploads/php/files/nv4nf675fhmvf7338g6jpma4mg/ripomorixuxolomejisel.pdfIn PDF document text
    • http://www.medical-psychology.gr/wp-content/plugins/formcraft/file-upload/server/content/files/1608c813f73397---notexedanefolapekif.pdfIn PDF document text
    • https://demircanticaret.com/userfiles/file/8296174107.pdfIn PDF document text
    • https://iword.de/userfiles/file/sutaxupom.pdfIn PDF document text
    • http://www.deco-interieure.com/userfiles/file/mekamiwigariruwike.pdfIn PDF document text
    • http://chiesamadremarsala.eu/userfiles/files/1017592404.pdfIn PDF document text
    • https://www.cr-sdc.org/wp-content/plugins/super-forms/uploads/php/files/f6a1aabeef7f8b32578dfe65efe95fb7/nativeboto.pdfIn PDF document text
    • https://agrolliance.ca/ckfinder/userfiles/files/6730693600.pdfIn PDF document text
    • http://www.neslihanonur.com/wp-content/plugins/super-forms/uploads/php/files/80f8b6fd7cbb05696389bd5b968e019d/jokasirodunirejanonumiw.pdfIn PDF document text
    • https://www.plsok.com/wp-content/plugins/super-forms/uploads/php/files/0fd4d684c68d29dc9c0f0a1d71f74c07/xaposaxoseximutusupixuv.pdfIn PDF document text
    • http://julieesteban.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608f6d9fdf5bb---56546066291.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/FevRqgeaUVY/uplcv?utm_term=baruch+spinoza+pdfPDF link annotation
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00021fe0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x21FE0 10656 bytes
SHA-256: 1c72e99bed730ac0a004ed8f56741a20dab381a68d99a976f21338d4437440b0