Malicious PDF — malware analysis report

Static analysis result for SHA-256 97da4b911d160c69…

MALICIOUS

PDF

69.4 KB Created: 2021-09-14 13:28:01 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: ff01cfc760ab11363cf6c2dffa5564d4 SHA-1: da7ab3f8ee2f323b70b0572d598c61c7c555ee48 SHA-256: 97da4b911d160c69fd2ef09da3ef862d36cbf59f5c20bd74e4cc84367d324d45
164 Risk Score

Malware Insights

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

The PDF contains embedded JavaScript and numerous external URIs, many of which point to compromised CMS upload storage or disposable hosting, indicating a link farm designed to redirect users. The ClamAV detection and ML classifier strongly suggest malicious intent, likely phishing or malware distribution. The embedded JavaScript is likely used to facilitate the redirection or exploit vulnerabilities.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9837

Heuristics 7

  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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=lego+marvel+superheroes+apk PDF link annotation
    • http://baovephuongtroi.com/vietkiendo/upload/file/36995969196.pdfIn PDF document text
    • http://rockycheng.com/ckfinder/userfiles/files/zuvekori.pdfIn PDF document text
    • http://detikakdeti.ru/img/file/jazumusajitisuwemet.pdfIn PDF document text
    • https://arnetbilgisayar.com/upload/ckfinder/files/voropowakutanevogiwapi.pdfIn PDF document text
    • https://archcosmeticstudio.com.au/wp-content/plugins/super-forms/uploads/php/files/63f1eaa6699c818fe318e96266ad818d/50828671635.pdfIn PDF document text
    • http://mayjack.com/upload/files/72540660785.pdfIn PDF document text
    • http://smingames.com/ckfinder/files/wusinavivokolalusogez.pdfIn PDF document text
    • https://vientangluc.com/upload/files/6629424418.pdfIn PDF document text
    • https://costabravas.com/uploads/localidades/files/76815274835.pdfIn PDF document text
    • https://humantouchtranslations.com/wp-content/plugins/formcraft/file-upload/server/content/files/1/1613c151bd6f95---bibup.pdfIn PDF document text
    • https://tramtron.vn/uploads/files/files/61634470300.pdfIn PDF document text
    • http://ducthoaudio.com/upload/files/benam.pdfIn PDF document text
    • http://plusk-car.com/js/upload/files/12707334123.pdfIn PDF document text
    • http://www.hkqi.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613d79a257b82---ripipuzuvera.pdfIn PDF document text
    • https://hardlineconstruct.ro/app/webroot/files/userfiles/files/27765815763.pdfIn PDF document text
    • http://bosch-elektronarzedzia.pl/catalog/file/56903403665.pdfIn PDF document text
    • http://svsteinfurth.de/radsportfiles/file/58509562298.pdfIn PDF document text
    • http://sotel-perm.ru/site/file/9587555819.pdfIn PDF document text
    • http://safiorida.dk/operatori/userfiles/file/54687696503.pdfIn PDF document text
    • http://www.sas.edu.mn/ckfinder/userfiles/files/bivosurudus.pdfIn PDF document text
    • http://pepinieres-soupe.com/userfiles/file/dovigajipewumo.pdfIn PDF document text
    • https://plentis.eu/ckfinder/userfiles/files/fixirejegovilemolebiti.pdfIn PDF document text
    • http://odnoklassniki-files.ru/images/uploads/files/23137556432.pdfIn PDF document text
    • http://lse.hu/userfiles/file/98893254490.pdfIn PDF document text
    • http://lichnyiybrand.ru/wp-content/plugins/formcraft/file-upload/server/content/files/1613fe4479627e---ximowibetenazuparakuw.pdfIn PDF document text
    • https://amkboiler.com/wp-content/plugins/super-forms/uploads/php/files/292nmh73k2rg8t3scqrq3ijqll/pulugafujima.pdfIn PDF document text
    • http://jiji.pgo.tw/pic/uploads/files/65419372555.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_off0000b35e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB35E 14704 bytes
SHA-256: b65a2cff65661199e84c0a7d164d157927f43cdf441c4026c3f0be199cd085a1
font_01_sfnt_off0000d790.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD790 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000efa7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEFA7 10620 bytes
SHA-256: a07c9453c9223a0df371ebc96c2b64b679acc0b805ec22fd096d730ea3fa2feb