Malicious PDF — malware analysis report

Static analysis result for SHA-256 c1fb5a62c94a676c…

MALICIOUS

PDF

84.1 KB Created: 2021-06-09 08:13:04 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-07
MD5: dd34afe6eb6a088dd60ceb86bfb73103 SHA-1: 65bbecc2eab3e668ccdacf2a0f7494593f7780fb SHA-256: c1fb5a62c94a676c554664b62abf135c84caa112be7f92a43c4029673e671162
196 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The PDF document contains a large number of embedded links, many pointing to compromised CMS upload directories and disposable hosting. This suggests a phishing or malware distribution campaign. The ClamAV detection and ML classifier further support its malicious nature. No scripts were extracted, but the primary attack pattern involves directing users to external malicious URLs.

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
  • PDF link to algorithmically-generated URL high PDF_RANDOM_URL_LINK
    PDF contains a clickable HTTP(S) link whose host looks algorithmically generated (pronounceable-random labels) and whose path/query carries a long high-entropy token. This is the randomized-redirector pattern of malspam phishing lures — the visible document is only a prompt — not a PDF parser vulnerability.
  • 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://crewmak.ru/uplcv?utm_term=biofloc+tilapia+pdf PDF link annotation
    • https://sumangold.net.vn/wp-content/plugins/super-forms/uploads/php/files/9rhbr41p1usob7rium27sbb7mb/jexapon.pdfIn PDF document text
    • https://angkorphotographyguide.com/userfiles/file/47052162107.pdfIn PDF document text
    • https://forkidsvietnam.vn/wp-content/plugins/super-forms/uploads/php/files/lf1j30icvdi6vstpfq1dgtkofa/xorazuduxam.pdfIn PDF document text
    • https://lawpropertyconsultants.co.uk/wp-content/plugins/super-forms/uploads/php/files/b525nu0kc9le2j3j6n9ki00iqj/kifaguxeki.pdfIn PDF document text
    • http://doublehappyvstheinfinitesadness.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607ac232e8225---lomivi.pdfIn PDF document text
    • https://saraelv.no/wp-content/plugins/formcraft/file-upload/server/content/files/1607a4d64211d3---xapanosizurereneripu.pdfIn PDF document text
    • http://cbgnfinance.com/userfiles/file/64319405791.pdfIn PDF document text
    • https://www.web2business.pt/wp-content/plugins/formcraft/file-upload/server/content/files/16083addfeaa7d---31439150167.pdfIn PDF document text
    • http://botanicgardenscafe.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/160a11074680ee---purodotizaj.pdfIn PDF document text
    • https://mithermomix.com.mx/wp-content/plugins/super-forms/uploads/php/files/833bef97a9e416d73cef742c6d16a2c0/87384190410.pdfIn PDF document text
    • https://stefandes.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607ed380ab587---148143515.pdfIn PDF document text
    • https://arizonapoolcontractor.com/wp-content/plugins/formcraft/file-upload/server/content/files/16089e8e2da26e---23228585320.pdfIn PDF document text
    • https://t4g.nasscomfoundation.org/wp-content/plugins/super-forms/uploads/php/files/cvfsidpo3uitjuudh921srhrr3/91523854646.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • 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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00010c24.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10C24 4924 bytes
SHA-256: a4f0d4e1b5295c539eb5b0de86cf85c236e409374862d4fb84609510e32881ee
font_01_sfnt_off00011d02.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11D02 11136 bytes
SHA-256: 9b8b6513b1052ccd05536ecdac2047d9e6f845475791f01c1993d323b337a7e3