Malicious PDF — malware analysis report

Static analysis result for SHA-256 e53b90893128c73f…

MALICIOUS

PDF

76.5 KB Created: 2021-09-12 11:24:55 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 0668b7dbf28ccf35e37f2ea4c03c236d SHA-1: cf63d10d29476fbcfd783733d48669f1c2afbedc SHA-256: e53b90893128c73ff9a500c28753d7a1965979471fb0101e6bcedf4ba2cb78f8
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a malicious PDF containing embedded JavaScript, as indicated by the PDF_JS heuristic. This script likely redirects the user to external URLs, as evidenced by the numerous PDF_URI and PDF_SEO_DISPOSABLE_LINK_FARM firings. The ML classifier and ClamAV detection strongly support its malicious nature, classifying it as a phishing trojan.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9992

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 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://longruiglass.com/ckfinder/userfiles/files/20210912_145700.pdf In PDF document text
    • http://abpjse.news-read.com/upload/files/14986530286.pdfIn PDF document text
    • https://www.limratechnologies.net/wp-content/plugins/formcraft/file-upload/server/content/files/1613acb04c1f9e---9537816522.pdfIn PDF document text
    • https://xn--fiqa735be48e.com/upload/files/26805858188.pdfIn PDF document text
    • https://skyfireconsulting.com/wp-content/plugins/super-forms/uploads/php/files/2lkc04a86bkhuouaib054bp63v/30951734240.pdfIn PDF document text
    • https://universal4shipping.net/userfiles/file/monizorez.pdfIn PDF document text
    • http://piannocreativo.com/js/new/fckeditor/userfiles/file/55761168176.pdfIn PDF document text
    • https://kop-trans.pl/uploads/userfiles/files/ladamamukevemi.pdfIn PDF document text
    • http://lifecare4all.com/upload/files/dezekulete.pdfIn PDF document text
    • https://www.adler-leitishofen.de/wp-content/plugins/formcraft/file-upload/server/content/files/1613ac15292789---ravope.pdfIn PDF document text
    • https://www.generalutilities.com/wp-content/plugins/formcraft/file-upload/server/content/files/161392120d1690---fipojujabur.pdfIn PDF document text
    • http://swhwsolution.it/ckeditor-ckfinder-integration/uploads/files/7210998885.pdfIn PDF document text
    • http://rymwid-training.com/userfiles/file/letegalanadafemenelebi.pdfIn PDF document text
    • http://singer-island-condos.com/userfiles/files/4432280474.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613d73982f242---41999353189.pdfIn PDF document text
    • http://kovofilm.cz/userfiles/file/takigebawetorubulodalokeb.pdfIn PDF document text
    • http://7166867.ru/ckfinder/userfiles/files/88949783999.pdfIn PDF document text
    • https://aqualibramontois.be/fckdownload/file/sitemegexeti.pdfIn PDF document text
    • http://ikra-ekb.ru/files/fckeditor/file/balotavujirafafuzikifat.pdfIn PDF document text
    • https://newdesert.pl/userfiles/file/modejuxifuxozewe.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/LPIa9PGmDLg/uplcv?utm_term=kirk+franklin+thank+youPDF 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_off0000c9dd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC9DD 17228 bytes
SHA-256: a6a9cd8eb4eb3bc9ed75173bb0c799c6bc2d7bb47ebc71f3b82ac58189ece284
font_01_sfnt_off0000f603.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF603 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00010e1a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10E1A 10308 bytes
SHA-256: 9f19c73025efce33944028f3c1b2e0fbd5ec20604a7f00cd193b84495d8aceda