Malicious PDF — malware analysis report

Static analysis result for SHA-256 c051a3e6eabdac4f…

MALICIOUS

PDF

76.0 KB Created: 2021-07-02 04:08:40 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-13
MD5: 71cf13fc122b8ce6786dcddcd1ed2c2b SHA-1: 62b7872f3b079c077874b62a3c0f694b874b96f5 SHA-256: c051a3e6eabdac4f7596cd10212b43e63595cc96e9ecf4a5a547a96db903bd54
156 Risk Score

Malware Insights

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

The PDF contains numerous external links, many pointing to compromised or disposable domains, indicating a link farm designed to lure users to malicious sites. The ClamAV detection and ML classifier strongly suggest malicious intent, likely related to phishing or malware delivery. No scripts were extracted, but the structure and URL patterns are consistent with a malicious PDF dropper.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9994

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://synerhu.ru/uplcv?utm_term=finding+slope+from+a+graph+worksheet+doc PDF link annotation
    • http://luvnchrlysenglishtoys.com/clients/861429/File/20030163195.pdfIn PDF document text
    • https://ktmcollege.org/public_html/userfiles/file/vulibuzanajamudero.pdfIn PDF document text
    • http://www.altrus.pl/wp-content/plugins/formcraft/file-upload/server/content/files/1607ddaa643f29---65740619645.pdfIn PDF document text
    • https://pankalconstructora.com/wp-content/plugins/formcraft/file-upload/server/content/files/16084a8930d1b9---miroromuwulatixifuwaba.pdfIn PDF document text
    • https://christianboudreau.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609408c7a8625---11153110475.pdfIn PDF document text
    • https://clubslotalmatriche.com/calcas/file/vesodujidemidaz.pdfIn PDF document text
    • http://amon-syotengai.com/userfiles/file/78491679095.pdfIn PDF document text
    • https://www.verpoort-bouw.be/wp-content/plugins/formcraft/file-upload/server/content/files/160814bc18ebea---46116358622.pdfIn PDF document text
    • http://www.recetasyconsejos.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a9595e9d72a---28461297458.pdfIn PDF document text
    • https://pankalconstructora.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a5069c5a94c---24371422162.pdfIn PDF document text
    • https://divorcioconsensual.com.br/wp-content/plugins/super-forms/uploads/php/files/053b99c81c422007d4567f0e38ea3e92/sasidugitijonikevebasi.pdfIn PDF document text
    • http://prplus4u.com/ckupload/files/vexupajusamarepirat.pdfIn PDF document text
    • https://www.masismarketing.com/wp-content/plugins/super-forms/uploads/php/files/f5819177a513f82332a7878e2e21b06e/48963140810.pdfIn PDF document text
    • http://www.sport-konyv.hu/userfiles/file/71185765530.pdfIn PDF document text
    • https://www.elementstraining.co.uk/wp-content/plugins/super-forms/uploads/php/files/21mah0ha3qb7hq7pedp5ka28q3/79992579522.pdfIn PDF document text
    • http://apricomm.com/userData/board/file/nobepagogewetele.pdfIn PDF document text
    • http://entone.es/wp-content/plugins/super-forms/uploads/php/files/2153414140ff0195152f1e57f2da80a4/41907061164.pdfIn PDF document text
    • http://kioskcondoweb.wpengine.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607399c0e5e19---38048741123.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_off0000c629.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC629 11220 bytes
SHA-256: af3b447195a41bed755383cdcc7f04f7e8573180e90b9151eac235fe376eee7b
font_01_sfnt_off0000e014.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE014 16512 bytes
SHA-256: 80b059d21712678c8e4c938c60d448395670ebde3a8271df432f65bcd31fc8f8
font_02_sfnt_off00010ae0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10AE0 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1