Malicious PDF — malware analysis report

Static analysis result for SHA-256 a964121a9c4eb989…

MALICIOUS

PDF

75.8 KB Created: 2021-09-15 05:06:51 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 25d77e8bef3dc30fa357561de7ebdd4f SHA-1: 14423c32da7ab6fc9b5f9e203286c73c64d9da7b SHA-256: a964121a9c4eb989bb4b3990f208ebefd0225f89ad1e1fde90d837531d3159d8
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. Heuristics identified it as a link farm, with many URLs pointing to compromised CMS upload directories and disposable hosting. This suggests the PDF is designed to lure users to external sites, likely for phishing or to download further malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9971

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://cachnhietcacham.vn/Images_upload/files/85697186086.pdf
    • https://earthchartercities.org/wp-content/plugins/formcraft/file-upload/server/content/files/1614122a6e8054---jebowa.pdf
    • http://hyundaihungthinh.com/uploads/images/files/mijiwasixavefuw.pdf
    • http://findingthegrey.com/userfiles/file/67795106529.pdf
    • https://priscar.com/documents/files/katolamowasepalewipoxel.pdf
    • http://bright-inter.com/file_media/file_image/file/4187712193.pdf
    • https://aguiapromocional.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/16136fedc05044---lisalovirivoviw.pdf
    • http://lexprikson.com/admin/style/images/userfiles/file/15086992710.pdf
    • https://berbagiangka.com/contents/files/tajixonilulafepe.pdf
    • https://mytekas.com/UserFiles/file/jobibewa.pdf
    • http://nifaelectronics.com/userfiles/file/47327841206.pdf
    • http://www.patricktennis.nl/wp-content/plugins/formcraft/file-upload/server/content/files/16140bea061465---55438030124.pdf
    • http://plkorea77.com/ckupload/files/nijigiderukama.pdf
    • https://koltoztetes-szallitas-lomtalanitas.com/ckfinder/userfiles/files/73048441040.pdf
    • https://www.web2business.pt/wp-content/plugins/formcraft/file-upload/server/content/files/161413f1cdbfb7---1130555148.pdf
    • https://bodymason.com/user_uploads/files/sudinugeza.pdf
    • http://awfiowv.love-mrt.com/upload/files/givipemexumubikesesita.pdf
    • http://mycoapaisyl.com/webimages/files/mituxudisaza.pdf
    • http://www.gonouvellezelande.com/files/walujimonapo.pdf
    • http://agilesolutions.in/uploads/fofugadoxobalilikezavimi.pdf
    • http://xn--9w3b270a7kf.kr/ckfinder/userfiles/files/60564193534.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/BkSY9tpko7c/uplcv?utm_term=streaming+the+walking+dead+world+beyond
    • 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_off0000c0c1.bin
968b51bc545375cca01e4c7d6a605464ca6cb4d3b3eb4947e3eaaa9f0fdbf987
pdf-font-stream PDF embedded font (sfnt) at offset 0xC0C1 18140 bytes
font_01_sfnt_off0000f04e.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xF04E 16792 bytes
font_02_sfnt_off00010865.bin
d89c3f293bc477e2597e8f6b62f5025d16fe88db595b3cdf85337ede9ac6c45b
pdf-font-stream PDF embedded font (sfnt) at offset 0x10865 11032 bytes