Malicious PDF — malware analysis report

Static analysis result for SHA-256 a65db32d0bddfcdc…

MALICIOUS

PDF

77.5 KB Created: 2021-09-16 09:05:01 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: ac12cebea55b4d574a2b960722784292 SHA-1: a9079bed0e3356a43a15c6721543bb43cb3daf86 SHA-256: a65db32d0bddfcdc8e0037d4e80e6139edf10f34996c0f08a354291ee2d6492b
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF file containing embedded JavaScript, which is a common technique for executing malicious code. It also features a large number of external URLs, many pointing to compromised WordPress sites, suggesting a link farm designed to redirect users to malicious content. The ClamAV detection and ML classifier further support its malicious nature, likely as a phishing or malware distribution lure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9953

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 https://infrive.ru/uplcv?utm_term=first+conditional+explanation+pdf
    • https://www.andyselfstorage.co.uk/wp-content/plugins/super-forms/uploads/php/files/hhikpf3uvsnu80pmni6mit54lb/59752376240.pdf
    • http://www.psstrecno.sk/wp-content/plugins/formcraft/file-upload/server/content/files/1613593af2e15f---zuvajagetopenupokelu.pdf
    • http://vitajeans.com/ckfinder/userfiles/files/bevisat.pdf
    • https://canionglobal.com/FCKeditor/file/nudapofesiraxukemeje.pdf
    • http://zezoalza.com/ckupload/files/retelepet.pdf
    • https://studio45.live/wp-content/plugins/super-forms/uploads/php/files/m7c1pltnov2ro8nfs0l2lrqrev/14281114094.pdf
    • http://xsteelstock.com/d/files/libewosawuworaza.pdf
    • http://www.moyekolodin.com/files/65619407583.pdf
    • http://www.creativitaecomunicazione.it/js/lib/ckfinder/userfiles/files/xegiladiwipukizozo.pdf
    • http://discarga.com/wp-content/plugins/formcraft/file-upload/server/content/files/161415e4d06726---46231940456.pdf
    • https://www.booster-p.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613fd52fb878c---18342356732.pdf
    • http://chothuexehochiminh.com/userfiles/file/31212703079.pdf
    • https://banerjeetourspecial.in/ckfinder/userfiles/files/ditovaxijo.pdf
    • http://wintec-samu.hu/uploads/files/gidegoxotajobukexixasuk.pdf
    • http://probeg2000.ru/files/userfiles/files/tawigedijewig.pdf
    • http://kino-cosmik.ru/sadm_files/20239319705.pdf
    • http://zzquansu.cn/d/files/fenawafifos.pdf
    • https://nsstore.mx/ckeditor/ckfinder/archivossubidos/files/nujolosiwugofiroxi.pdf
    • http://clairerolo.com/userfiles/file/51452771396.pdf
    • https://www.tunnel.de/files/uploaded/file/21756967688.pdf
    • http://mn-print.ru/ckfinder/userfiles/files/janadivoluwa.pdf
    • http://denkobarbell.com/_upload/files/jinezab.pdf
    • https://sca-eagleegg5k.com/ckfinder/triplebuserfiles/file/lavidoladivotovivitewisaj.pdf
    • 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://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000cc6b.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xCC6B 16792 bytes
font_01_sfnt_off0000e482.bin
cdf925a4d7d33f05bd99e0564bbeedc8fd602e37f24ec71791fe6a8cd37aac0d
pdf-font-stream PDF embedded font (sfnt) at offset 0xE482 10692 bytes
font_02_sfnt_off0000fd27.bin
b783f1476926227a58976512629ece07c5c5fb209e0b9bd21597eb3a9b2e1aa5
pdf-font-stream PDF embedded font (sfnt) at offset 0xFD27 16812 bytes