Malicious PDF — malware analysis report

Static analysis result for SHA-256 cac8161d9bf84075…

MALICIOUS

PDF

82.2 KB Created: 2021-09-21 20:49:12 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: c5176aac6068aef2af4b2f05199f4e2a SHA-1: b7c927bfc5863524f27bcd375ed50cf2b8a76f7d SHA-256: cac8161d9bf840751f7a0f2e0e051912158826ebc11da680e2133801e8d40fac
156 Risk Score

Malware Insights

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

The PDF file was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, directing users to multiple external URLs, some hosted on compromised WordPress sites. The presence of numerous links, including one pointing to a compromised CMS upload, suggests an attempt to redirect users to malicious content or phishing pages.

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 https://creativetalentnetwork.com/ckfinder/userfiles/files/67392840941.pdf In PDF document text
    • http://aibasylhet.edu.bd/app/webroot/ckfinder/userfiles/files/82564526066.pdfIn PDF document text
    • http://ebbers-schilderwerken.nl/uploads/files/gitaj.pdfIn PDF document text
    • https://advik.net/userfiles/file/fogobotavax.pdfIn PDF document text
    • http://warungmimpishio2.com/contents/files/moluwanos.pdfIn PDF document text
    • https://salondumariagededijon.com/userfiles/file/75548469507.pdfIn PDF document text
    • https://ntct-dz.com/ckfinder/userfiles/files/15253457374.pdfIn PDF document text
    • http://chatyzvule.cz/uploads/pebanajizasol.pdfIn PDF document text
    • https://event-connections.net/wp-content/plugins/formcraft/file-upload/server/content/files/1614980100c6bc---difive.pdfIn PDF document text
    • http://mtcongnghiepxanh.com/upload/fckimagesfile/fofopoxozazunenu.pdfIn PDF document text
    • http://thumpamonpally.com/userfiles/file/diponog.pdfIn PDF document text
    • http://safetyassessmentsolutions.co.uk/ckfinder/userfiles/files/xajimaxawadinoveku.pdfIn PDF document text
    • https://pgp-puh.hr/fck_media/file/tufozutidem.pdfIn PDF document text
    • http://restavratorstvo.com/ckfinder/userfiles/files/xodaranusasisiwasuwage.pdfIn PDF document text
    • http://alphasigmaoverseas.com/userfiles/file/56805579094.pdfIn PDF document text
    • https://www.nhabe.com.vn/ckfinder/userfiles/files/pifejis.pdfIn PDF document text
    • http://zhizhencn.com/filespath/files/20210905180334.pdfIn PDF document text
    • http://weldingplaza.com/files/file/17608022848.pdfIn PDF document text
    • http://nikolabartakova.cz/files/file/80403287295.pdfIn PDF document text
    • http://www.insurancedirectcanada.ca/wp-content/plugins/formcraft/file-upload/server/content/files/161467cc8a49ee---fovimijewu.pdfIn PDF document text
    • http://www.majorisinvestimentos.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1613257405a62f---76661095792.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/BkSY9tpko7c/uplcv?utm_term=uninstall+app+bawaan+androidPDF 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_off0000dcf3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDCF3 10484 bytes
SHA-256: a9dc2daacc8352bb9502d6f62ab12659c23fe9abe800729dcdfbcf373c202db3
font_01_sfnt_off0000f4aa.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF4AA 18072 bytes
SHA-256: ea65b0ff872e3bfbb43535a9383920a488a9b4fa9c04d6cf37fe126638b3be85
font_02_sfnt_off00012345.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12345 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1