Malicious PDF — malware analysis report

Static analysis result for SHA-256 f8b0167acefe862b…

MALICIOUS

PDF

75.4 KB Created: 2021-09-03 22:25:30 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: 972bfb78fe46a10561d4003e05acd80f SHA-1: 5e9b8e88c3b32f6210f897d32a07c09824b7af09 SHA-256: f8b0167acefe862be5fccc432dec3ed42c5833ea0008cd2d01c1cfdac30285be
156 Risk Score

Malware Insights

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

The ML classifier and ClamAV detection strongly indicate maliciousness. The PDF contains numerous links, many pointing to compromised or disposable domains, which is characteristic of phishing or malware distribution schemes. The presence of external URI heuristics and link farm indicators further supports this attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9971

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://birnagarcollege.in/userfiles/file/32514900726.pdf In PDF document text
    • http://855solution.com/htdocs/cljr/data/files/nitafezive.pdfIn PDF document text
    • http://www.zopfitravel.com/wp-content/plugins/formcraft/file-upload/server/content/files/16071dfe08023c---nugenewiwovu.pdfIn PDF document text
    • http://crystal-lamp.ru/uploads/files/junojuv.pdfIn PDF document text
    • http://dodici12.ru/wp-content/plugins/super-forms/uploads/php/files/6u1dsub9kutml79v9e5eosq8q6/7585069567.pdfIn PDF document text
    • http://goldmustang.ru/files/files/vanidomarapibivixizetogok.pdfIn PDF document text
    • http://puginternational.com/ckfinder/userfiles/files/fadixu.pdfIn PDF document text
    • http://duythuc-bearing.vn/uploads/userfiles/file/93426297063.pdfIn PDF document text
    • http://esoftland.com/userfiles/file/seraxe.pdfIn PDF document text
    • http://geobigoni.it/userfiles/files/17282813577.pdfIn PDF document text
    • http://toyotarent.tw/FileData/ckfinder/files/20210821_898F21E2CDEA8B3B.pdfIn PDF document text
    • http://pravkniga.ru/files/userfiles/files/dezepudixol.pdfIn PDF document text
    • http://kpdb.org/userfiles/files/vuxufuxesulo.pdfIn PDF document text
    • http://gsoam.ge/wp-content/plugins/formcraft/file-upload/server/content/files/160a62f95dbcf7---zezunomamabatawu.pdfIn PDF document text
    • https://digireg.dk/upload/gavowefi.pdfIn PDF document text
    • http://ahzycw.com/upload_fck/file/2021-8-23/20210823190000900885.pdfIn PDF document text
    • https://robertmatzuzi-massagetherapist.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/160bd61e42b047---60749592046.pdfIn PDF document text
    • https://www.lumisolar.pe/wp-content/plugins/formcraft/file-upload/server/content/files/160dbca2ef31e2---kemizemujuruzelituma.pdfIn PDF document text
    • http://heydarbaba.org/resimler/files/gesuximagojit.pdfIn PDF document text
    • http://modelkyujin.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612efe15e8c3c---68354492332.pdfIn PDF document text
    • http://www.yourhealthyourchoice.org/wp-content/plugins/formcraft/file-upload/server/content/files/160b3865fd028d---duvijikepigevevifudoro.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/3CAf4wW3hvY/uplcv?utm_term=domain+and+range+worksheet+%2311PDF 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_off0000c34c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC34C 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000db63.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDB63 10828 bytes
SHA-256: 9957996cbc2143f163b1a88b7ef29b6e13f7f623105b14250fd92f9be2ce2d79
font_02_sfnt_off0000f404.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF404 17392 bytes
SHA-256: 879ba55ed7f92be7f223efe9ca7e0d33427ea90c64e67ef56408803b3cd4a729