Malicious PDF — malware analysis report

Static analysis result for SHA-256 a97f8fae503c4f46…

MALICIOUS

PDF

93.0 KB Created: 2021-08-14 10:17:53 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: ca73f0f617af03600c955f1d67e0b057 SHA-1: 2fedca9624169cd8a1b066646ebbb67d74d3dea4 SHA-256: a97f8fae503c4f46eb14cfb37ba8758cba3d7cbc783496beb64e359d742432e7
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 WordPress sites, suggesting a phishing or malware distribution attempt. The ML classifier and ClamAV detection strongly indicate malicious intent. The document body is heavily obfuscated and unreadable, but the presence of link farms and compromised CMS uploads points to a malicious redirection scheme.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9990

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://cructi.ru/uplcv?utm_term=%D1%81%D0%BA%D0%B0%D1%87%D0%B0%D1%82%D1%8C+%D0%B1%D0%B5%D1%81%D0%BF%D0%BB%D0%B0%D1%82%D0%BD%D0%BE+%D0%B4%D1%80%D0%B0%D0%B9%D0%B2%D0%B5%D1%80+%D0%B4%D0%BB%D1%8F+%D0%BF%D1%80%D0%B8%D0%BD%D1%82%D0%B5%D1%80%D0%B0+samsung+ml-2015
    • https://njsolarpower.com/wp-content/plugins/super-forms/uploads/php/files/181fe402284641482a2790800f6c1757/wokozalejirolagufitu.pdf
    • http://www.reroofingbrisbaneqld.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/160a60907c202e---30226547242.pdf
    • http://leap-egypt.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a61bc47ba62---88680055921.pdf
    • https://motelandratecuci.ro/userfiles/file/26038623520.pdf
    • https://dagvandearchitectuur.be/_files/file/48720435862.pdf
    • https://alphaveneers.co.uk/wp-content/plugins/super-forms/uploads/php/files/d08ed8ce75773e5c7dd05b97b6650802/26803337595.pdf
    • https://tungqibiotech.com/upfiles/editor/files/99724539084.pdf
    • http://samsung-service-center.ru/uploads/files/gowef.pdf
    • http://sutinlawkrabi.com/ckfinder/userfiles/files/57499367757.pdf
    • https://avenirpourtous.fr/wp-content/plugins/formcraft/file-upload/server/content/files/1606f5f91c511d---xabifadidoxawavitaj.pdf
    • https://gmnavarra.es/ckeditor/files/dapojigesegesa.pdf
    • http://xn--or3bi2da319p.com/upload/fckeditor/file/pefatowalegebifurujewi.pdf
    • http://pierrevillers.fr/mairie_files/file/62180482376.pdf
    • https://transcendenceit.com/wp-content/plugins/super-forms/uploads/php/files/70bc71c1de8314dd47b4eaedcaf6c90b/70891598723.pdf
    • http://aj-logistics.com/stock/userfiles/file/12365266455.pdf
    • http://makaeximworld.com/wp-content/plugins/formcraft/file-upload/server/content/files/160943b684d5f6---xudez.pdf
    • http://ndt-tl.ru/upload/file/14605309766.pdf
    • http://pebyte.com/wp-content/plugins/super-forms/uploads/php/files/bccgragq2c7jct3ngtqvre90fi/36145820278.pdf
    • https://tirthmobile.com/wp-content/plugins/super-forms/uploads/php/files/vsanok275aah6evq5pcfjhc2cq/59928468821.pdf
    • http://micruts.org/userfiles/file/81662070399.pdf
    • http://bmcsteel.com/uploads/baiviet/files/78853664956.pdf
    • https://hgb.se/filer/file/82965997607.pdf
    • https://www.basur-tedavisi.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606f10bd35d2f---25249023460.pdf
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000eef2.bin
3be7a6891f2045753242c6ce2bf95445e12fc2daef77821acd1b7ca50d01243f
pdf-font-stream PDF embedded font (sfnt) at offset 0xEEF2 12636 bytes
font_01_sfnt_off00010d2b.bin
ae106f737ca62917cf0d4539fda5eff9a9a4166f9d238725910146bf8931cf92
pdf-font-stream PDF embedded font (sfnt) at offset 0x10D2B 24396 bytes
font_02_sfnt_off000149f9.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x149F9 16792 bytes