Malicious PDF — malware analysis report

Static analysis result for SHA-256 87c71e2911ede07b…

MALICIOUS

PDF

83.8 KB Created: 2021-09-04 09:50:11 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 192983ae857a5d464c10a3aaf441294a SHA-1: 25f2e5a2c9a405488f67b76cf7a1e7944df04958 SHA-256: 87c71e2911ede07be61559d414d3d13de3bf3f09622255b68230e594bb6a5484
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript and numerous external URIs, many of which point to compromised CMS upload storage or are part of a link farm on disposable hosting. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or distributing further malware. The embedded JavaScript is likely used to facilitate redirection to these malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9955

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://unitytradefze.com/ckfinder/userfiles/files/39566525421.pdf In PDF document text
    • http://www.stratcareerservices.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608f0fcdcd70e---votavirobiji.pdfIn PDF document text
    • https://bitree.ru/ckfinder/userfiles/files/10146608451.pdfIn PDF document text
    • http://gilendor.cz/userfiles/file/7243376255.pdfIn PDF document text
    • http://worldofpacifiers.com/editor_uploads/system/files/38536740996.pdfIn PDF document text
    • https://gearforfree.com/wp-content/plugins/super-forms/uploads/php/files/9uub2p5fkd4g4c4c2toikc6pcl/kipiso.pdfIn PDF document text
    • https://rjpexport.com/files/33955089547.pdfIn PDF document text
    • http://xsteelstock.com/d/files/7627047944.pdfIn PDF document text
    • http://caacoding.net/wp-content/plugins/formcraft/file-upload/server/content/files/160e562a7cba75---bogefonivobotoga.pdfIn PDF document text
    • https://arerp.kr/data/file///88032651.pdfIn PDF document text
    • https://hohsingfiber.com/ufiles/files/73660955234.pdfIn PDF document text
    • http://ersatzmonitor.de/userfiles/file/77932577948.pdfIn PDF document text
    • http://funperm.ru/content/file/siwibarenidivuxar.pdfIn PDF document text
    • https://www.ccps.mx/wp-content/plugins/super-forms/uploads/php/files/b9e7e0955d2c2ec7a594fc4da0fd550a/82273891642.pdfIn PDF document text
    • https://oteaexpert.fr/cite_imgs/file/besenamu.pdfIn PDF document text
    • http://www.colegiometa.net/home/wp-content/plugins/formcraft/file-upload/server/content/files/160c3fdfe0062a---gebulebaduraxitilubikow.pdfIn PDF document text
    • http://akcjonariusz.com/UserFiles/file/16254718708.pdfIn PDF document text
    • http://www.lightingandhvacexpo.com/wp-content/plugins/super-forms/uploads/php/files/fd45c8369f1306a1fe46577847d6394d/47754013841.pdfIn PDF document text
    • http://security-m.jp/tool/images/file/91903768530.pdfIn PDF document text
    • https://www.iieng.org/editor/ckfinder/userfiles/files/medox.pdfIn PDF document text
    • http://energy-labels.nl/userfiles/file/gujururujogebaketukovid.pdfIn PDF document text
    • https://yarsan.ru/wp-content/plugins/super-forms/uploads/php/files/ee430f3635e19897b7fe36efceb09580/13993525279.pdfIn PDF document text
    • http://xn--9w3b11kh5l.com/ckupload/files/nodametenegodegore.pdfIn PDF document text
    • http://everbeenmagnet.com/js/upfiles/files/zuvafekebobe.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/ngfLrbzwjls/uplcv?utm_term=dictionnaire+d%27interpr%C3%A9tation+des+r%C3%AAves+pdfPDF 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_off0000dbef.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDBEF 10980 bytes
SHA-256: ddd5808ae20f463141e68910b4dabbff43ff642317e6f54c96b25ede487f5f11
font_01_sfnt_off0000f4f6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF4F6 19680 bytes
SHA-256: b819d7253941f65ab09a52c2929e6d8c77b919136f9102dc1f022ad0b8845222
font_02_sfnt_off00012707.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12707 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1