Malicious PDF — malware analysis report

Static analysis result for SHA-256 3ff10371f735a2bc…

MALICIOUS

PDF

83.4 KB Created: 2021-09-14 14:14:33 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-27
MD5: 01b55dd6abcb179d119bb6b9b44c74f7 SHA-1: 842be5aaecacdf636bc7de23ea3d34bd4b5f968d SHA-256: 3ff10371f735a2bc559dee19a576dac4f123271a40a5988c044de5f99373822c
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF file flagged as malicious by ML classifiers and ClamAV. It contains numerous embedded URLs, many pointing to other PDF files on distinct domains, indicating a link farm. One URL, http://chataphan.com/file_media/file_image/file/zoler.pdf, is identified as part of a link farm on disposable hosting. While no scripts were explicitly extracted, the PDF structure and embedded links suggest an attempt to redirect users to malicious content, likely for phishing or malware delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://chataphan.com/file_media/file_image/file/zoler.pdf In PDF document text
    • http://munnartourism.com/uploads/file/64179932779.pdfIn PDF document text
    • https://geneticapanama.com/userfiles/file/lerovabiweve.pdfIn PDF document text
    • http://becucci.it/userfiles/files/32122693590.pdfIn PDF document text
    • http://flyingkirin.com/uploadfiles/file/101708416743.pdfIn PDF document text
    • https://vatlieutaphu.com/upload/files/17420328781.pdfIn PDF document text
    • http://bigdoughpizza.com/uploads/files/fevulanobuxud.pdfIn PDF document text
    • http://cegled.varosom.hu/userfiles/files/bupuf.pdfIn PDF document text
    • http://leton.pl/userfiles/file/82959232698.pdfIn PDF document text
    • http://nriloan.jctoursandtravels.in/files/rutifipadafemevema.pdfIn PDF document text
    • http://nhakhoauytinhaiphong.com/upload/files/3221944142.pdfIn PDF document text
    • http://kiszelyugyvediiroda.hu/docs/file/73110353076.pdfIn PDF document text
    • http://kientrucsangtrong.com/plus/files/17828308665.pdfIn PDF document text
    • http://crystaltrade.hu/data/file/56703799327.pdfIn PDF document text
    • https://thanaclusterwestgate.leaddeehub.com/userfiles/files/gitoja.pdfIn PDF document text
    • https://jills.reviewz.eu/app/webroot/files/userfiles/files/nadeladolaxawekinopad.pdfIn PDF document text
    • http://startent.ru/SITE/files/editor/file/73961134766.pdfIn PDF document text
    • http://younewstoday.com/task/userimages/file/48595641020.pdfIn PDF document text
    • https://www.habitat-morvan.fr/ckfinder/userfiles/files/46467601789.pdfIn PDF document text
    • https://100tmt.com/uploadimage/files/20210905055616.pdfIn PDF document text
    • http://korea-seals.com/ckfinder/userfiles/files/jobetusolovonaru.pdfIn PDF document text
    • https://szalkasszorutacskok.hu/app/webroot/files/content/files/446501497.pdfIn PDF document text
    • https://briljant-maleri.se/UserFiles/files/62325373553.pdfIn PDF document text
    • https://dodatnojamstvo.com/userfiles/file/93417059645.pdfIn PDF document text
    • http://bright-inter.com/file_media/file_image/file/zajojujowopate.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/S30rS-6n6vg/uplcv?utm_term=android+screen+went+blackPDF 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_off0000e05c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE05C 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f873.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF873 10660 bytes
SHA-256: 3051132277681c43e4eecb294a4b36c240c37d7a0ade37972e741b38c6ae5266
font_02_sfnt_off0001111a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1111A 18120 bytes
SHA-256: 33dac94b685bf11ba12e5b873b50ff363d73fa2f488dcfc76788320179e8458a