Malicious PDF — malware analysis report

Static analysis result for SHA-256 38f4b42cbc1c57e2…

MALICIOUS

PDF

84.3 KB Created: 2021-08-21 11:53:34 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 9283b9e87694877d8709aa963a3ff423 SHA-1: a64e67b193bc8f200eed6abc6c8fd1fcccfccda4 SHA-256: 38f4b42cbc1c57e2f09a5f2df79c03547ffa01476c3a28cdb5bf96fbbfa21e1c
156 Risk Score

Malware Insights

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

The sample is identified as a malicious PDF by multiple heuristics and a machine learning classifier. It contains numerous external links, many pointing to compromised WordPress upload storage or disposable hosting, suggesting a link farm designed to redirect users. The ClamAV detection as 'Pdf.Phishing.Trojan' further supports its malicious nature. No scripts were extracted, but the PDF structure and link farm indicate a phishing or malware distribution attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9980

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://ed-web.cz/userfilesfile/37492804157.pdf
    • http://tnslib.su/userfiles/files/rodugasimadevekok.pdf
    • https://guapa2.com/admin/fck/file/fuguja.pdf
    • http://conelser.hu/fck_uploads/file/72094479692.pdf
    • http://phuclocvienjsc.com/uploads/image/files/nebudifak.pdf
    • http://msslink.ru/userfiles/files/59108334785.pdf
    • http://nuitsdartistes.eu/images/file/xadubuwanolugovuger.pdf
    • http://feach.ie/images/uploads/file/53357949902.pdf
    • http://www.loicadesacavem.pt/wp-content/plugins/formcraft/file-upload/server/content/files/160ac670025d48---73501035730.pdf
    • https://esperanzadeavila.com/fotos/file/darefozupexakotilerupar.pdf
    • http://iphysiology.ru/upload/dopate.pdf
    • http://burattinojatek.hu/userfiles/file/48445600637.pdf
    • http://www.canadiantreasurer.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c148fb4af5d---23210887645.pdf
    • https://realestateconnect.us/wp-content/plugins/super-forms/uploads/php/files/6qp2vqrfpaq8fk6jb0dj8i06l6/81619682351.pdf
    • http://myjobcareer.net/userfiles/file/2021062619432773499.pdf
    • http://rwdwebwebdesign.com/img-aim/files/65306851811.pdf
    • http://privateeducation.sg/verzsape/demo/upload/admin/files/66965839649.pdf
    • https://sancarspune.com/wp-content/plugins/super-forms/uploads/php/files/6b6e425576523e3c6501c7e1c1b52ad3/gimimirukurixopatopo.pdf
    • https://www.hotwaterfactory.com.au/wp-content/plugins/super-forms/uploads/php/files/923d41e2faa4d26c289c20acfd9316ad/21854579662.pdf
    • http://thefarmatarapahoecounty.com/userimages/99344078064.pdf
    • https://matras-matrasych96.ru/admin/ckfinder/userfiles/files/49072939390.pdf
    • https://www.jemelectric.com/wp-content/plugins/formcraft/file-upload/server/content/files/16074d1103d48c---konamazonomijulosegi.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/6naE_Nh8_CY/uplcv?utm_term=is+innisfree+green+tea+seed+serum+good+for+acne
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000e28b.bin
05f073cba29585217e07693c6d386a57c9e4eddf3c8f31798c2ea1812055d64f
pdf-font-stream PDF embedded font (sfnt) at offset 0xE28B 10824 bytes
font_01_sfnt_off0000fb4d.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xFB4D 16792 bytes
font_02_sfnt_off0001135f.bin
eb03dbf7b8fc6f2f885a395900de577ad11baffdc1c3f359eb5b72d744787e5d
pdf-font-stream PDF embedded font (sfnt) at offset 0x1135F 17432 bytes