Malicious PDF — malware analysis report

Static analysis result for SHA-256 d836039a5de4ebc2…

MALICIOUS

PDF

75.4 KB Created: 2021-07-04 06:21:19 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-14
MD5: 6c90c0ae4f99ced14d6da7b8fc5a75ae SHA-1: f71955c98590c829892fd857b91876676da35223 SHA-256: d836039a5de4ebc22df17bd4560e31c57b9ed41c54c346f8f84dfb456347becb
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many of which point to compromised CMS upload directories, indicating a link farm designed to host or redirect to malicious content. The ML classifier and ClamAV detection strongly suggest malicious intent, likely related to phishing or malware delivery through these links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9963

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 https://www.gsccn.it/wp-content/plugins/formcraft/file-upload/server/content/files/160bfcd2f9e04e---42342394700.pdf In PDF document text
    • https://taichielite.com/louis/taichi/ckfinder/userfiles/files/78017120657.pdfIn PDF document text
    • https://liantoong.com/archive/upload/files/55965959206.pdfIn PDF document text
    • https://www.stamfordtaxis.com/wp-content/plugins/super-forms/uploads/php/files/848gup15p746k08phbvqtn3vrh/duxibuxoborizobamir.pdfIn PDF document text
    • https://dm288.rs/slicice/file/derojipexurowezutidafap.pdfIn PDF document text
    • https://textolinguisticsolutions.com/upload/editor/file/wowefavuwujenenazax.pdfIn PDF document text
    • http://portaldo.eu/contenuti/upload/file/pepawopojigazasefuxonowi.pdfIn PDF document text
    • http://ipjanah.ir/wp-content/plugins/super-forms/uploads/php/files/8g4jk8hln3elvatp7jk9kr6kf2/korofifanedajan.pdfIn PDF document text
    • http://taiwan-casters.com/userfiles/file/73458023872.pdfIn PDF document text
    • http://www.tif.cn/wp-content/plugins/super-forms/uploads/php/files/q0q4vnve8q9eo240r4cudckia6/77170899312.pdfIn PDF document text
    • http://bettaletroom.com/file_media/file_image/file/79459263763.pdfIn PDF document text
    • http://crmrealty360degree.in/userfiles/file/21672089769.pdfIn PDF document text
    • http://www.darvidproperty.com/news/file/kabedametevadugudavezen.pdfIn PDF document text
    • http://alliance-ltd.com/userfiles/fazavelubojeju.pdfIn PDF document text
    • http://vasamo.org/pds/userfiles/files/gutedovowujo.pdfIn PDF document text
    • http://accessprecision.com/userfiles/file/gatuwe.pdfIn PDF document text
    • https://comesa.com.pe/wp-content/plugins/super-forms/uploads/php/files/6eknt4nn6ii93dj4nbb92i3dh5/rapefuz.pdfIn PDF document text
    • http://mim2010.ru/userfiles/file/rikuba.pdfIn PDF document text
    • http://hgbs.de/userfiles/file/18157619843.pdfIn PDF document text
    • http://rokakisreunion.com/clients/a/a8/a85ca1e4cfc2bb88d767af442173b437/File/ninupi.pdfIn PDF document text
    • http://atek-ent.com/upload/file/detuzogazubewubusavawub.pdfIn PDF document text
    • https://sipare.com.ar/wp-content/plugins/super-forms/uploads/php/files/40etprvunq47su0ijse78i8c2r/pasonuzov.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/BvfzZFkJO3s/uplcv?utm_term=percy+jackson+the+sea+of+monsters+read+onlinePDF 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_off0000c33b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC33B 16736 bytes
SHA-256: 4faa7356171bc88d3cb4aea869df8295ff9767e69c69f1ba00e63427cc3c154f
font_01_sfnt_off0000ee48.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEE48 11080 bytes
SHA-256: 8828af9789d001e0d229536458723d4f42af6a037237a8ee9ae25068b7fa9c9a
font_02_sfnt_off000107e9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x107E9 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1