Malicious PDF — malware analysis report

Static analysis result for SHA-256 a8f4d06a2b5a2273…

MALICIOUS

PDF

92.6 KB Created: 2021-10-18 01:58:39 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-24
MD5: 755d9fc04ff73003e9e6e00f179d80bd SHA-1: 9600af630365eaaf9ff627a0c7233e7f41f3ec55 SHA-256: a8f4d06a2b5a22732650ec35f11e24cd3d6031c68a0c539d2406ce73d13067e1
156 Risk Score

Malware Insights

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

The PDF contains a large number of embedded URLs, many of which point to compromised CMS uploads or disposable hosting, suggesting a link farm or SEO poisoning attempt. The ML classifier and ClamAV detection strongly indicate malicious intent, likely related to phishing or distributing further malware through these links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9965

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://daqing-jewelry.com/uploads/files/202109220325272803.pdf In PDF document text
    • http://desushibar.com/userfiles/file/90092816299.pdfIn PDF document text
    • https://aceold.lrsinc.co/userfiles/file/19143824572.pdfIn PDF document text
    • https://hondaotohaiphong.vn/upload/files/44659893031.pdfIn PDF document text
    • http://grafiport.com/userfiles/file/76213257023.pdfIn PDF document text
    • http://tuzvedo.hu/elemek/file/83996523795.pdfIn PDF document text
    • https://inchirierielicopter.ro/wp-content/plugins/formcraft/file-upload/server/content/files/1614b6db2dbb99---853522575.pdfIn PDF document text
    • https://torrentclub.vip/wp-content/plugins/super-forms/uploads/php/files/qrhghkbh6ri7ighp2bogvph2h9/1763860989.pdfIn PDF document text
    • http://isvpro.com/custom/files/8700169838.pdfIn PDF document text
    • http://www.trimbleexpress.sk/wp-content/plugins/formcraft/file-upload/server/content/files/16166c13311983---bidaliluro.pdfIn PDF document text
    • https://liantoong.com/archive/upload/files/81218902985.pdfIn PDF document text
    • https://damsindia.org/admin/uploads/file/64983189926.pdfIn PDF document text
    • https://learnrkb.jugalbandiresearch.com/ckfinder/userfiles/files/jabakajovagebekanapam.pdfIn PDF document text
    • https://www.temsilcisitesi.com/wp-content/plugins/formcraft/file-upload/server/content/files/1615aa0a54de3b---43058243902.pdfIn PDF document text
    • https://legacytwirlers.cornerfamily.com/userfiles/files/48723832824.pdfIn PDF document text
    • http://atol-res.pl/uploads/file/17893578327.pdfIn PDF document text
    • https://constructor.dilen.top/upload/files/45342450736.pdfIn PDF document text
    • http://carzip.biz/files/uploads/files/33462319953.pdfIn PDF document text
    • http://3gr-group-com.gbintl.com/ci/userfiles/files/kugak.pdfIn PDF document text
    • https://www.cylinder96.ru/admin/ckfinder/userfiles/files/mujovum.pdfIn PDF document text
    • http://drsuthichai.com/userfiles/files/pujun.pdfIn PDF document text
    • https://adrfarysz.pl/userfiles/file/10635738236.pdfIn PDF document text
    • http://saigonford3s.com/uploads/2021-09-25/images/files/zumowutuxup.pdfIn PDF document text
    • https://edcasys.com/ci/userfiles/files/89631499299.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Gsjc/~3/UsNeCLCzgYg/uplcv?utm_term=how+is+an+explicit+memory+different+from+an+implicit+memoryPDF 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_off00010524.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10524 11076 bytes
SHA-256: 145b1e8161fc862d5006f430e19090f3f3e25112ccf6f55181ce9455415d8a31
font_01_sfnt_off00011ef7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11EF7 17372 bytes
SHA-256: 8ae280dfa5cd0da684ed1c63a1d21289e82d1c94bd7499f1bd866f9c4151ddcc
font_02_sfnt_off00014bd5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x14BD5 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1