Malicious PDF — malware analysis report

Static analysis result for SHA-256 f97621f977596876…

MALICIOUS

PDF

71.9 KB Created: 2021-06-24 18:50:01 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-27
MD5: 56117d44f2e52b61639f7e00970343b8 SHA-1: ec778a90c8e4b61df1cf3ab3502fcaaee80f7759 SHA-256: f97621f97759687624e0eb3baa75bfa6eb99f6d0601229c4c641e7c96d4cc42e
156 Risk Score

Malware Insights

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

The file was detected as a malicious PDF by ClamAV and an ML classifier. Heuristics indicate it functions as a link farm, directing users to multiple compromised WordPress upload storage locations and other disposable hosting sites. The embedded URLs and the nature of the heuristics suggest an intent to lead users to phishing or malware distribution pages.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

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 http://cokhibaosang.com/media/ftp/file/18803296325.pdf In PDF document text
    • http://www.siscard.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608dc147e45b8---xuxamadiboratubizawemijij.pdfIn PDF document text
    • http://ophtalmic-overnight.fr/wp-content/plugins/formcraft/file-upload/server/content/files/1606d502d05923---93754945738.pdfIn PDF document text
    • http://baanpowertrain.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607bb594ba10c---44406265903.pdfIn PDF document text
    • https://ratsimae.eemedia/contents/file/48700099817.pdfIn PDF document text
    • http://terapie-psi.ro/wp-content/plugins/formcraft/file-upload/server/content/files/160b876ba91878---vowewububoragila.pdfIn PDF document text
    • http://gingerwooddesign.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b730112b39b---75558492324.pdfIn PDF document text
    • http://www.jhannahs.com/wp-content/plugins/formcraft/file-upload/server/content/files/160999e93d8ba7---50375596078.pdfIn PDF document text
    • http://grani-tonkogo-mira.ru/wp-content/plugins/super-forms/uploads/php/files/4161efd9ea322f1a30846c2b1945b79d/73368576982.pdfIn PDF document text
    • http://alanurturizm.com/rsm/files/wavidikelevodobevanaguwa.pdfIn PDF document text
    • https://uniqrelation.com/userfiles/file/muvugaze.pdfIn PDF document text
    • https://goldenparadisestsimons.com/wp-content/plugins/super-forms/uploads/php/files/aa7a4253126f944fbafac1abebb91808/73697211158.pdfIn PDF document text
    • https://vakukh.ru/wp-content/plugins/super-forms/uploads/php/files/233e7f4feefeed699bd00185b7f53e1c/97377759734.pdfIn PDF document text
    • http://mintaialuminum.com/d/files/8483954339.pdfIn PDF document text
    • http://www.pianoszimmermann.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160720747adeb2---kojoxetabudokopafebufuna.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/FevRqgeaUVY/uplcv?utm_term=hyperfocus+book+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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000dd24.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDD24 5172 bytes
SHA-256: 7e74d33b9ee6a6be165df53f1b66eca9ef2657ba1580d5cbb143bcae7424b060
font_01_sfnt_off0000eed3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEED3 10676 bytes
SHA-256: 4a4d9baa4f1ba2e863daf37d65e20875e051c3fd7f1fa4806e5fb594725627db