Malicious PDF — malware analysis report

Static analysis result for SHA-256 cfff8a7fd2c5a058…

MALICIOUS

PDF

81.6 KB Created: 2021-10-07 15:17:13 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 7feb30a40a5456939b9925e68ee435ac SHA-1: dbbd2837dc7a8205d612626b7186adc6f9bc0533 SHA-256: cfff8a7fd2c5a058f22e7924564eeb997f40579dbaa9ca3cd1caab3367749045
156 Risk Score

Malware Insights

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

The PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It contains numerous links, many pointing to compromised CMS uploads or disposable hosting, suggesting a link farm designed to redirect users to malicious sites. The presence of these links and the overall structure strongly suggest a phishing or malware distribution campaign.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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://immobilieninvestors.com/userfiles/file/dujinejarameto.pdf
    • https://www.hdcorp.com.br/wp-content/plugins/super-forms/uploads/php/files/4rab46nnebmo2f4aabusunhcdp/29271903300.pdf
    • https://dermo.com/wp-content/plugins/formcraft/file-upload/server/content/files/16158589ce333e---tukitamasinafofutivud.pdf
    • https://careerroots.net/ckfinder/userfiles/files/zasufapajimal.pdf
    • https://astoraccessories.com/uploads/ckfinder/files/bedesakujiredazapasuvudo.pdf
    • http://kondicionery-ivanteevka.ru/upload_picture/file/mezemimuvuzogazukov.pdf
    • http://zadonskiy.ru/wp-content/plugins/formcraft/file-upload/server/content/files/161573fd117273---64126705829.pdf
    • http://mfplus.ba/wp-content/plugins/formcraft/file-upload/server/content/files/161578294a3378---201944030.pdf
    • http://kyea.org/imageuploads/17898477900.pdf
    • http://fecoil.com/userfiles/file/pifepukibomi.pdf
    • http://www.norestim.ro/wp-content/plugins/formcraft/file-upload/server/content/files/1614c0e6f6b07b---45701821281.pdf
    • http://t-cso.com/upload/file_folder/file/jigitukekisubojilu.pdf
    • http://nprofit.hk/userfiles/tafojimomutatunutaterofu.pdf
    • https://gotoko.com/cmsv2/upload/files/74720778877.pdf
    • http://pkynfe.net/userfiles/file/80944002642.pdf
    • http://ucinnovation.ru/admin/ckfinder/userfiles/files/rubobunuvidali.pdf
    • http://aburobocon2019.mnb.mn/uploads/files/85300376879.pdf
    • https://prettygreekvillas.com/admin/fckeditor/editor/filemanager/connectofile/tobaguf.pdf
    • http://hz-karavany.cz/ckfinder/userfiles/files/59601628570.pdf
    • http://ksklinika.ru/ckfinder/userfiles/files/kosadojugisavus.pdf
    • https://mahanakhon.pacedev.com/ckupload/files/27515153625.pdf
    • http://bsinteriordesigner.com/userfiles/files/25596203380.pdf
    • https://zlatartopalovic.rs/files/domasifiviwidevegukefofag.pdf
    • http://wwsm-us.com/files/file/75933260758.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/BkSY9tpko7c/uplcv?utm_term=hospital+administration+projects+pdf
    • 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_off0000d696.bin
bf04d436f3692faf10c1a1807fe04c228e709db72e2515607c85a7796d30cd6c
pdf-font-stream PDF embedded font (sfnt) at offset 0xD696 10904 bytes
font_01_sfnt_off0000efb3.bin
538016670a2b72f54647ffc468458d86ff5f1c7dfa16fb5bdab4b7adf68ed3c2
pdf-font-stream PDF embedded font (sfnt) at offset 0xEFB3 18688 bytes
font_02_sfnt_off0001205a.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x1205A 16792 bytes