Malicious PDF — malware analysis report

Static analysis result for SHA-256 eecf21baea2b3f66…

MALICIOUS

PDF

81.4 KB Created: 2021-09-07 21:35:51 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: ef6c270971f1632d586341691ab03399 SHA-1: 5fb1722d60cb02652115d7c326679c585dc409c4 SHA-256: eecf21baea2b3f66e45e558df87ac27dda828ed4e422849402b0ac75d9ad1694
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 WordPress upload directories or disposable hosting, indicating a link farm designed to redirect users to malicious sites. ClamAV and ML classifiers confirm its malicious nature, likely for phishing or malware distribution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

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 https://krisoc.ru/uplcv?utm_term=uae+social+studies+textbook+pdf PDF link annotation
    • http://luxe-pools.fr/i/File/sotesal.pdfIn PDF document text
    • https://www.sixteengrams.com/wp-content/plugins/super-forms/uploads/php/files/7smssvr2ct986tkifoaigl08l0/gunogaluli.pdfIn PDF document text
    • http://ubest.ru/images/file/7912821031.pdfIn PDF document text
    • https://transcendenceit.com/wp-content/plugins/super-forms/uploads/php/files/a9734607049f180c3c6d17befb5e2c67/jixufozibigobubona.pdfIn PDF document text
    • http://zuche0551.com/upload/file/5698483117.pdfIn PDF document text
    • https://xlspandoek.nl/userfiles/file/vitabipen.pdfIn PDF document text
    • https://namastehealth.in/wp-content/plugins/super-forms/uploads/php/files/e5k4r6lt5ugeap31gtab4jbl5r/7715008124.pdfIn PDF document text
    • http://autohondl.cz/userfiles/file/weloduzupubukiva.pdfIn PDF document text
    • http://www.fsnn.se/wp-content/plugins/formcraft/file-upload/server/content/files/16071b460bca13---gofisizelabotomijenolibol.pdfIn PDF document text
    • http://bioterapiazabiegi.pl/obrazy/file/58786660775.pdfIn PDF document text
    • http://planbmedia.hufiles/wofuwezurel.pdfIn PDF document text
    • https://egyiksem.hu/uploads/file/76935360820.pdfIn PDF document text
    • http://al-farh-iq.com/upload/userfiles/file/numofimomolijajo.pdfIn PDF document text
    • http://apsons.eu/files/file/nuguruvifozefonodo.pdfIn PDF document text
    • https://www.temsilcisitesi.com/wp-content/plugins/formcraft/file-upload/server/content/files/160d21218883ec---fanizonafuwatutuwobe.pdfIn PDF document text
    • http://khaskhaan.mn/uploads/userfiles/files/dobitezokojunobekamiwemeb.pdfIn PDF document text
    • http://acecaalcoy.com/userfiles/file/dutivumuvevo.pdfIn PDF document text
    • http://bizwd.com/wp-content/plugins/formcraft/file-upload/server/content/files/160f38cc02946f---sakegevatugegep.pdfIn PDF document text
    • https://indiachristian.org/uploads/files/vonixazutunizejig.pdfIn PDF document text
    • http://sakurahoaanhdao.com/webroot/img/files/73048875186.pdfIn PDF document text
    • http://goodslib.com/userfiles/files/tufexerexes.pdfIn PDF document text
    • https://elbag.net/wp-content/plugins/super-forms/uploads/php/files/f111ceb536dd843e6802e31b7da06131/ziduvewamosas.pdfIn PDF document text
    • https://expungemyrecordnj.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608ab911d5edf---60169116861.pdfIn PDF document text
    • http://thetsaban3watnuea.com/UserFiles/file/nuxosigifozasux.pdfIn PDF document text
    • http://geoplan.su/userfiles/file/50780334152.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_off0000da79.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDA79 17008 bytes
SHA-256: 33a9d45a57a515426f77c88fbbb5df6b3681022360c25d9165bda42b309c1928
font_01_sfnt_off0001067a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1067A 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00011e91.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11E91 10852 bytes
SHA-256: 31bf8297deb6119322baf9e63e0f5cf08353486b6243add90ca42422787ba87c