Malicious PDF — malware analysis report

Static analysis result for SHA-256 171da89e06b51767…

MALICIOUS

PDF

84.8 KB Created: 2021-09-19 10:29:09 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: cac662e36747a1bffef0d9118bf8c469 SHA-1: 835df2b971edb9e01a64cc1e1527bb66768c5719 SHA-256: 171da89e06b517675ccce80d777cdcf6903323fa1afb7fe7c4f1e07cc2828f6a
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous links, many of which are hosted on disposable domains or compromised CMS uploads, suggesting a link farm designed to distribute malicious content. The presence of a ClamAV detection for 'Pdf.Phishing.Trojan' and ML classifier flagging further supports its malicious nature. The document body, though heavily obfuscated, contains references to 'wkhtmltopdf' and a date, indicating it was likely generated programmatically to host these links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9985

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://grawerlik.pl/userfiles/file/pujagarosudumamuluta.pdf In PDF document text
    • https://www.nitdgp.ac.in/uploads/userfiles/files/zajinilofafu.pdfIn PDF document text
    • http://vietcem.vn/public/default/ckeditor/files/bokivafagupojobodineg.pdfIn PDF document text
    • https://pomtco.com/technical/files/file/10636037332.pdfIn PDF document text
    • http://marcth.pl/media/fck/file/xujudamulaz.pdfIn PDF document text
    • http://akcjonariusz.com/UserFiles/file/dezuraz.pdfIn PDF document text
    • https://value.ae/userfiles/file/nenugixipivazuxalewolazoj.pdfIn PDF document text
    • http://www.cuadernos.in/wp-content/plugins/formcraft/file-upload/server/content/files/16141210f6cd4e---mapefole.pdfIn PDF document text
    • http://hum-lucknow.org/test/fckeditor/file/mixosozidinoxutojak.pdfIn PDF document text
    • http://www.finanzanlagen-honorarberatung.de/wp-content/plugins/formcraft/file-upload/server/content/files/1613e86d9d4eb4---pabewezegizepuv.pdfIn PDF document text
    • http://zezoalza.com/ckupload/files/46729427199.pdfIn PDF document text
    • http://genarchi.com/data/temp/file/27541441075.pdfIn PDF document text
    • http://tnslib.net/userfiles/files/6268716891.pdfIn PDF document text
    • http://softwarefactory.nl/images/file/jamikuzokafapitedazofe.pdfIn PDF document text
    • https://mimpishio1.com/contents/files/dafolubisiwulaloxuvoxilam.pdfIn PDF document text
    • https://journeywithmypet.com/ckfinder/userfiles/files/11278288257.pdfIn PDF document text
    • https://webmedcentralplus.com/userfiles/file/89697876072.pdfIn PDF document text
    • https://signatureshreyas.in/userfiles/file/vogolo.pdfIn PDF document text
    • http://vanprodukt.cz/UserFiles/File/33316990580.pdfIn PDF document text
    • https://ebal.ro/app/webroot/files/userfiles/files/valugenadunixexedenogube.pdfIn PDF document text
    • https://hoovermaids.com/wp-content/plugins/super-forms/uploads/php/files/273b15356c61ba05e09911b9e25b1a7d/16671048871.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/GLLx1DTH0VQ/uplcv?utm_term=clash+of+clans+gems+hack+app+downloadPDF 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_off0000e569.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE569 17784 bytes
SHA-256: 9dc1032b126148748e1572e613034563cf0f69c6608b0c7e2aad30bc57813915
font_01_sfnt_off00011403.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11403 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00012c1a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12C1A 10988 bytes
SHA-256: d98334e0eecd7ab769a851aa402451f08a2df56fcb4a973eccdf9fad2e79a8ad