Malicious PDF — malware analysis report

Static analysis result for SHA-256 cb1665fc815eeff6…

MALICIOUS

PDF

71.8 KB Created: 2021-05-10 06:26:28 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 4578b6b262d90deedb955a4f0e4fb442 SHA-1: 3681a68ccfe1eddc99ba830010ecbeaef4715279 SHA-256: cb1665fc815eeff678be68a8bc3af0e4be7c706c4bb560110cb77883fcd50d20
196 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution T1059.007 JavaScript

This PDF document was flagged by a machine learning classifier and ClamAV as malicious, exhibiting characteristics of a phishing and trojan delivery mechanism. The heuristic 'SE_BROWSER_INSTALL_LURE' indicates the document likely prompts the user to install a fake browser update or extension. Several URLs point to compromised WordPress sites hosting PDF files, suggesting a link farm used to distribute the malicious document or redirect to further malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

Heuristics 7

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • Browser extension / update installation lure high SE_BROWSER_INSTALL_LURE
    Document tells the user to install a browser extension, plugin, viewer, or browser update to view content — a common social-engineering path for credential theft and malware installation
  • 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://argentum.com/wp-content/plugins/super-forms/uploads/php/files/mrsqcfmb473htvqib3gvapghsu/giwekan.pdf
    • http://avonsteel.com/UserFiles/file/woxakemirepemumepome.pdf
    • https://law.com.sg/wp-content/plugins/super-forms/uploads/php/files/6275cf15b0dc83dc576ee168aa842a83/vasasusopixolikafuler.pdf
    • http://www.acefence.com/wp-content/plugins/formcraft/file-upload/server/content/files/16070853f47bb4---77273677791.pdf
    • http://www.majorisinvestimentos.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/16088b240d106f---wezug.pdf
    • https://dtcprojects.com.au/wp-content/plugins/super-forms/uploads/php/files/iho6ai8k6l28u0j4gjdr71cju2/gesajopomoxa.pdf
    • https://dsodrecital.com/wp-content/plugins/formcraft/file-upload/server/content/files/160873868e7369---10213822364.pdf
    • http://sazjah.com/wp-content/plugins/formcraft/file-upload/server/content/files/16083eb261429a---duvizifeb.pdf
    • http://az4group.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1609602da7e5c3---91744239934.pdf
    • http://informerfitness.com/wp-content/plugins/super-forms/uploads/php/files/2e7c17445478e00cd2d91e163d229ca8/92405512336.pdf
    • https://www.bluegreenshouseboats.in/wp-content/plugins/formcraft/file-upload/server/content/files/16086ea8723b74---jevaxanakelug.pdf
    • https://postscriptproductions.com/wp-content/plugins/formcraft/file-upload/server/content/files/16092023f0dd8e---56258517450.pdf
    • https://leesman.com/wp-content/plugins/super-forms/uploads/php/files/e3221e6f4724761a7523ff256074c1fe/64117657954.pdf
    • https://www.parkgest.ch/wp-content/plugins/formcraft/file-upload/server/content/files/16098a4dc8755d---teroruk.pdf
    • http://www.lightingandhvacexpo.com/wp-content/plugins/super-forms/uploads/php/files/21e8d0dd7e6ab383a1de278646dbe597/zuvivisaxugavofamalu.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • https://feedproxy.google.com/~r/Uplcv/~3/Om9ozkHLxGw/uplcv?utm_term=windows+10+updates+manually
    • 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://scripts.sil.org/OFL

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000dbf8.bin
d5f86c5dd36b028486de61b470a1bdcc6561754f03ab308e95aec923ffae5a48
pdf-font-stream PDF embedded font (sfnt) at offset 0xDBF8 5412 bytes
font_01_sfnt_off0000ee71.bin
288e843a63b675fc18d6ed00a12a064799a0d14158739e29c8d98a52190b5e8d
pdf-font-stream PDF embedded font (sfnt) at offset 0xEE71 10372 bytes