Malicious PDF — malware analysis report

Static analysis result for SHA-256 1b6f4a198472f8b7…

MALICIOUS

PDF

84.9 KB Created: 2021-06-24 15:44:08 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-16
MD5: 5c44d27541252783bbb83991dcb7ec85 SHA-1: 473913e95f52d50d45d2f6e70ae75d05aaddeab5 SHA-256: 1b6f4a198472f8b76e632d7eb10ce5d873a16b0d3dd5d3dc93d5501303994d24
156 Risk Score

Malware Insights

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

The sample is a PDF file that contains numerous links to external websites, many of which are hosted on compromised WordPress sites or disposable domains. The document body, though heavily obfuscated, suggests a lure related to 'Gina Wilson All Things Algebra 2014 Answer Key' to trick users into visiting these malicious URLs. The ML classifier and ClamAV detection strongly indicate malicious intent, likely phishing or malware distribution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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://queure.ru/uplcv?utm_term=gina+wilson+all+things+algebra+2014+answer+key+pdf PDF link annotation
    • http://www.linkkorea.co.kr/wp-content/plugins/formcraft/file-upload/server/content/files/1609c410599964---jabomefelanudo.pdfIn PDF document text
    • http://eugensa.lt/app/webroot/uploads/userfiles/files/xerefirisufun.pdfIn PDF document text
    • http://bezpieczna-strefa.pl/wp-content/plugins/super-forms/uploads/php/files/3973ed276b1a131a883d698220c29962/21635459567.pdfIn PDF document text
    • http://i-dron.cz/data/file/joxidiwekozefe.pdfIn PDF document text
    • http://quickfix-poland.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609481fab01e7---wogeraj.pdfIn PDF document text
    • http://www.photobreak.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160b4ff240b3e1---31471195439.pdfIn PDF document text
    • http://xn--o39a91gvwm83kbsn.com/FileData/ckfinder/files/20210612_EFD68C16B6560D75.pdfIn PDF document text
    • https://www.federatedlighting.com/wp-content/plugins/super-forms/uploads/php/files/9bece3df66e0c386f3a23efd0493df93/rewaxumanovaji.pdfIn PDF document text
    • http://webbuilders.com/files/file/namobolafifomojejozipepid.pdfIn PDF document text
    • http://victorylimo1.com/wp-content/plugins/formcraft/file-upload/server/content/files/160741b6fe31f4---55798731141.pdfIn PDF document text
    • https://www.properties-thassos.com/wp-content/plugins/super-forms/uploads/php/files/5ummaj2eliq5jsku3mlhu7g5us/56966712030.pdfIn PDF document text
    • http://www.pirac.org/wp-content/plugins/super-forms/uploads/php/files/2ad7c1a65f30662e08ce598666cfe930/43133746181.pdfIn PDF document text
    • https://action-roofing.com/wp-content/plugins/super-forms/uploads/php/files/c593c67139dc6b14c58017220aef17e7/33378617354.pdfIn PDF document text
    • https://dmvassociates.com/wp-content/plugins/super-forms/uploads/php/files/3cd64e36869f129b255d3578fc800c60/67965189929.pdfIn PDF document text
    • http://homenet-spb.ru/userfiles/file/bekeradigu.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_off0001071c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1071C 6144 bytes
SHA-256: 014470ea7a5cdcecfc1779cd212675aff167661e5b7159dbd0aab7828983f798
font_01_sfnt_off00011c1f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11C1F 11924 bytes
SHA-256: 77a2dd01dbaa612e4493aff4588294884f5a3de92864068f6ea67ddec19173f7