Malicious PDF — malware analysis report

Static analysis result for SHA-256 51e40443ac5541c1…

MALICIOUS

PDF

78.7 KB Created: 2021-09-03 19:47:50 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: 597ef3d61cc2df027d263c8a2283bccf SHA-1: b128eca256a0c75e02adf2c758bca94854ceb9e6 SHA-256: 51e40443ac5541c14b6c4fcf0f50c98328855b2087dfa791763a6ad685b08a9f
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, suggesting a phishing or malicious redirection scheme. The ML classifier and ClamAV detection strongly indicate malicious intent, likely to lure users to malicious sites or download further malware. The presence of link farms on disposable hosting further supports this. No scripts were extracted, limiting the analysis of direct execution vectors.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9978

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://drmiamiconnect.com/wp-content/plugins/super-forms/uploads/php/files/5c5a3ec715dcdcf56af0a4c6c15828e7/nugenobaragevine.pdf In PDF document text
    • http://rockhouseschool.com/rockhouse/uploads/files/4368302407.pdfIn PDF document text
    • http://champagne-marc-chauvet.com/images/files/37519599158.pdfIn PDF document text
    • https://whereestar.com/marinarubicon/admin/file/19677674316.pdfIn PDF document text
    • http://www.primalegal.eu/wp-content/plugins/super-forms/uploads/php/files/tu5auq3ve4nlhn7a4r99kdu9k3/90071806021.pdfIn PDF document text
    • https://equalland.com/uploads/File/venakolerigenejapon.pdfIn PDF document text
    • https://ville-saintleonard.fr/pdf/kawudawar.pdfIn PDF document text
    • https://bursakaynak.com/userfiles/file/10700954006.pdfIn PDF document text
    • http://www.onekaddy.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a662ffbda68---45447140379.pdfIn PDF document text
    • http://www.insight-assessment.com/ckfinder/userfiles/files/vobazozepov.pdfIn PDF document text
    • http://www.ncstarim.com.tr/wp-content/plugins/super-forms/uploads/php/files/6tblu9j9ir047dt1h80vos0567/xalojegunojumi.pdfIn PDF document text
    • http://csc0535.com/userfiles/file/20210727020230_og8y80.pdfIn PDF document text
    • https://ridersshop.it/file/8941772107.pdfIn PDF document text
    • https://vinisfarm.com/wp-content/plugins/super-forms/uploads/php/files/c4b50207b226c08c86d49b47811b8f8b/62393999.pdfIn PDF document text
    • https://zweiund40.com/wp-content/plugins/super-forms/uploads/php/files/mtimkd4a4i50edou968o5t7hal/zedozawujoxebinu.pdfIn PDF document text
    • https://limpiezasinasel.com/userfiles/files/xasidinovasitowoze.pdfIn PDF document text
    • http://www.adanakursmerkezi.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a004739f0b6---84384776603.pdfIn PDF document text
    • http://orourkelawoffice.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/goboxiz.pdfIn PDF document text
    • http://europeanprofservices.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608b5d6019c39---92944123754.pdfIn PDF document text
    • https://plswa.com/wp-content/plugins/super-forms/uploads/php/files/16e4ea61ebed7902a00cdeb1377fbade/sufawurixoxabetuguja.pdfIn PDF document text
    • http://polymer-optix.de/userfiles/file/56198961964.pdfIn PDF document text
    • http://logistra.fr/ressource/site-image/files/musiva.pdfIn PDF document text
    • https://carsen.sk/editor_uploads/system/files/93612162716.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/LPIa9PGmDLg/uplcv?utm_term=separation+techniques+pdf+ks3PDF 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 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000cd89.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCD89 11256 bytes
SHA-256: e2409094868210836642a56d3c769c9516cce7ababecee869538442659f4d5e2
font_01_sfnt_off0000e7ac.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE7AC 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000ffbe.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFFBE 17580 bytes
SHA-256: bf18c4ca9f873f2f935c1a7b12ec9831e6e4571474a6c03cf83a038960803df2