Malicious PDF — malware analysis report

Static analysis result for SHA-256 c1c603351e5669ad…

MALICIOUS

PDF

79.8 KB Created: 2021-09-16 17:26:01 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 40a744db0dc6c99f24535373b6379f74 SHA-1: 4e4e994b7b79df9ec3b5599af34e9dd7cf1ebcea SHA-256: c1c603351e5669ad96e7e40d40390525d030e4d08457e4528d1cf416dc6d3a82
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF file was flagged by multiple heuristics as a link farm, with several URLs pointing to compromised CMS uploads and disposable hosting. The ML classifier and ClamAV also identified it as malicious. The embedded URLs suggest an attempt to redirect users to external sites, likely for phishing or to download further malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

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 https://elicopter-de-inchiriat.ro/wp-content/plugins/formcraft/file-upload/server/content/files/161416ba56cb78---jijenapox.pdf In PDF document text
    • http://bjerkelunden.org/content/files/userfiles/file///vijadizivoxib.pdfIn PDF document text
    • https://aannemingsbedrijfbarthulsbosch.nl/userfiles/file/84180512366.pdfIn PDF document text
    • http://daming-school.com/userfiles/file/virivovonejizoxe.pdfIn PDF document text
    • https://mackbeks.com/files/file/nunijavuvifaxowasigafore.pdfIn PDF document text
    • https://biodent.ro/m4fm_files/m4news/ck-uploads-files/94826534621.pdfIn PDF document text
    • http://eviljoy.com/UserFiles/File/rodixarofudagepekasize.pdfIn PDF document text
    • https://zagi.hr/files/33798750775.pdfIn PDF document text
    • http://dermalab.pl/userfiles/file/zasuxebatovaxuwole.pdfIn PDF document text
    • https://gpuhub.net/wp-content/plugins/super-forms/uploads/php/files/jl06qf21fen0oli6hfou0pe0k2/10719830424.pdfIn PDF document text
    • https://mp2020.csysadmin.com/ckfinder/userfiles/files/repesilefo.pdfIn PDF document text
    • http://cupta.org/userfiles/files/20210916081705.pdfIn PDF document text
    • http://tandartsindex.nl/images/uploads/sidof.pdfIn PDF document text
    • http://tokyoracing.hu/userfiles/file/kidaxalapagawibud.pdfIn PDF document text
    • http://pyroglobal.sk/app/webroot/files/userfiles/files/dejasufa.pdfIn PDF document text
    • https://www.traveltimevipp.com/wp-content/plugins/super-forms/uploads/php/files/0d8683cb22b9693143c0f05819573a66/kilibiluzabeki.pdfIn PDF document text
    • http://yokohama-model.com/userfiles/files/raguviwetezifimerax.pdfIn PDF document text
    • http://www.bestlifepolicy.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/161361b65ec3d3---38529468164.pdfIn PDF document text
    • http://malopolskiszlakwinny.pl/upload/File/79145474783.pdfIn PDF document text
    • http://lamardaegu.com/upfile/user/file/79939897132.pdfIn PDF document text
    • http://jaatkinson.com/userimages/93938560221.pdfIn PDF document text
    • http://lammensfilip.be/uploads/files/nojufafozolewipu.pdfIn PDF document text
    • http://www.ebsjosepirosamaria.com/wp-content/plugins/formcraft/file-upload/server/content/files/16143480ea80e5---reruxijukujiwufegi.pdfIn PDF document text
    • http://www.johnknox.ch/wp-content/plugins/formcraft/file-upload/server/content/files/16136bc3789ee8---ketanogomugif.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/S30rS-6n6vg/uplcv?utm_term=remove+google+account+from+androidPDF 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_off0000d31a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD31A 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000eb2c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEB2C 17732 bytes
SHA-256: 001cd2c318e5bd7c3e1c8d124f11493e475f5cebf98e9df684e0f4b78f46578d
font_02_sfnt_off00011884.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11884 10864 bytes
SHA-256: 0697045d82fea7a390d94d1c11dc00de1e289c38082e16c7f52a1e833e520e36