Malicious PDF — malware analysis report

Static analysis result for SHA-256 a6d4f99e114adb7a…

MALICIOUS

PDF

70.7 KB Created: 2021-09-04 16:13:40 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: 5f15c2b2296978464ccb4d784465028f SHA-1: 70f52b9d80d9abf972716ae61287acf966cd5070 SHA-256: a6d4f99e114adb7a225670449a7cb9e8e1c2366bf357b30864153a57c744bc5b
96 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 WordPress sites and disposable domains, indicating a link farm or redirection scheme. The ML classifier strongly flagged this PDF as malicious, and the heuristic firings confirm its nature as a link farm. The primary purpose appears to be directing users to external, potentially malicious, content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9954

Heuristics 5

  • 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://kiuanai.com/userfiles/file/jilexemozawabosexamig.pdf In PDF document text
    • http://unipell.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160a1fb268955f---29648123997.pdfIn PDF document text
    • http://ulsantour.com/FileData/ckfinder/files/20210725_F16D0FBABE9CE5C9.pdfIn PDF document text
    • http://life-worldwide.org/assets/uploads/files/73263674169.pdfIn PDF document text
    • https://visualarchive.bg/files/19385118282.pdfIn PDF document text
    • http://hhtaitung.com/CKEdit/upload/files/radaniwimesel.pdfIn PDF document text
    • https://radiosmile.hu/upload/file/kupudisinuveraxubox.pdfIn PDF document text
    • http://www.shipsupply.co.mz/wp-content/plugins/formcraft/file-upload/server/content/files/160bcc3dcae9a7---dikujaxot.pdfIn PDF document text
    • http://www.jobsincrete.gr/images/_user_na/file/tixusabosomeguzutafew.pdfIn PDF document text
    • http://arch-teh.com/pic/userfile/nudagutufinegete.pdfIn PDF document text
    • https://www.jemelectric.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b1a548d98c1---kubunebupolafu.pdfIn PDF document text
    • http://studiotecnicomaglio.it/userfiles/files/77982066042.pdfIn PDF document text
    • http://kibbkw.com/uploads/file/71687298145.pdfIn PDF document text
    • https://resonanceacteurs.nl/userfiles/file/xadididabu.pdfIn PDF document text
    • http://hondaotohaiphong.vn/upload/files/62859216949.pdfIn PDF document text
    • https://allmassage.net/upload/file/20210510153030.pdfIn PDF document text
    • http://keigan-productions.com/clients/863431/File/vegijijona.pdfIn PDF document text
    • https://gbeequestriansurfaces.com/wp-content/plugins/super-forms/uploads/php/files/1kmf4h8smov1b7ieduqb4d2hjq/90551377843.pdfIn PDF document text
    • https://chiataiec.com/userfiles/Proj_Name//files/34354200096.pdfIn PDF document text
    • http://leguido.net/files/rewufadozixorubenusasud.pdfIn PDF document text
    • http://hellnocancershow.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b98a848ed9d---39612333491.pdfIn PDF document text
    • https://ivfnna.gr/wp-content/plugins/super-forms/uploads/php/files/328a5fa2c694de2ec83dc7371a391a40/99769198014.pdfIn PDF document text
    • http://veterinariomauracotti.it/userfiles/files/19063365168.pdfIn PDF document text
    • https://alakharia.com/public_html/userfiles/file/6819096976.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/A3Ryygt5BCM/uplcv?utm_term=gitarre+akkorde+lieder+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://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_off0000b2e8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB2E8 16704 bytes
SHA-256: 652f233a767538031bdbe41cc6c83d64ae4dcf8baebf7f94629d840563f8e44a
font_01_sfnt_off0000dca4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDCA4 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000f4bb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF4BB 10352 bytes
SHA-256: 2204d55a6febcf99aa10e6cae5d8c6efa80f50bbc014f43bdf20228f53fa696f