Malicious PDF — malware analysis report

Static analysis result for SHA-256 c51131745986aa77…

MALICIOUS

PDF

69.6 KB Created: 2021-09-28 18:21:23 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-23
MD5: 4a052140632f3a6b8cd1e27ab05dfe5a SHA-1: 26032ef5f2d7f65f5c66c2034721f4616c4bedc2 SHA-256: c51131745986aa7708bc17563e45703398c12a47ef342ede58f73d38eb01f67d
156 Risk Score

Malware Insights

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

This PDF was flagged by ML classifiers and ClamAV as malicious. It contains numerous links, many pointing to compromised CMS upload storage or disposable hosting, suggesting a link farm designed to redirect users. The document body is heavily obfuscated, preventing analysis of its specific content, but the overall structure and heuristic firings indicate a phishing or malware distribution attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9982

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://ace-pharm.com/upload/files/bakabopugudebaza.pdf In PDF document text
    • https://www.arc-welding.co.uk/wp-content/plugins/super-forms/uploads/php/files/ratn2tidcf2scmk74uqoaie3cu/sugawuratowupesetele.pdfIn PDF document text
    • https://ihotel2b.com/upfiles/editor/files/xetapiduxumatibosalojuge.pdfIn PDF document text
    • https://samowar.ch/upload/file/63263634713.pdfIn PDF document text
    • http://ablerexthailand.com/userfiles/files/46950122389.pdfIn PDF document text
    • https://carcarnet.com/home/sandbox/domains/hkdance.tritek.hk/public_html/ckfinder/userfiles/files/68455930619.pdfIn PDF document text
    • https://borgopitti.it/userfiles/file/ludane.pdfIn PDF document text
    • https://hv2barrier.com/application/third_party/ckfinder/userfiles/files/81015817901.pdfIn PDF document text
    • https://hankilfood.com/userfiles/file/20210925050057.pdfIn PDF document text
    • http://777mto.info/contents/files/28193431272.pdfIn PDF document text
    • https://ubitanduk.com/contents/files/55968206083.pdfIn PDF document text
    • https://clic-essc.ch/ck/ckfinder/userfiles/files/difodujug.pdfIn PDF document text
    • http://www.armstrongre.com/files/files/worusado.pdfIn PDF document text
    • https://purefeeling8.com/data/file/momifevanolasogokojitat.pdfIn PDF document text
    • https://zakarpattya-tour.com/upload/58209712455.pdfIn PDF document text
    • http://shahgrp.com/uploads/pixos.pdfIn PDF document text
    • https://www.rath-catering.de/wp-content/plugins/formcraft/file-upload/server/content/files/1613d469f8cca9---jomifujamapelif.pdfIn PDF document text
    • http://nomayaku.com/userfiles/file/suvegu.pdfIn PDF document text
    • http://montaze.org/democms/userfiles/file/bofexub.pdfIn PDF document text
    • https://chowdhurytourism.com/ckfinder/userfiles/files/49962043080.pdfIn PDF document text
    • http://mariautonoleggiomarsala.it/userfiles/files/ledafus.pdfIn PDF document text
    • http://www.gametimecatering.com/wp-content/plugins/formcraft/file-upload/server/content/files/161449a0dd7f38---xaxapu.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/zMnd8XtcwSM/uplcv?utm_term=android+import+sms+from+simPDF 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_off0000b025.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB025 16284 bytes
SHA-256: b33732de06cae0ceb44bcc5328fdd7c13776bb1044de5580cdc7d629764e24fc
font_01_sfnt_off0000d96c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD96C 10300 bytes
SHA-256: fb3e74780615bce1974a288c35876ff2f7f90756ee66521f7a55cfebed3245b2
font_02_sfnt_off0000f090.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF090 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1