Malicious PDF — malware analysis report

Static analysis result for SHA-256 a718080eacb6c423…

MALICIOUS

PDF

73.0 KB Created: 2021-09-02 01:28:32 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: 1831ad15554574b6fbf44a7d91d261e9 SHA-1: 62f21e1a23a3c44c5e3b9dbd40fda0ac3b6bdddb SHA-256: a718080eacb6c423ad94d44d864ab44f4e2491a199d9f392527af1ecdbf0e15c
156 Risk Score

Malware Insights

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

The PDF was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. It contains numerous embedded URLs, many pointing to compromised CMS upload directories, suggesting an attempt to lure users to malicious content or downloads. The document body is heavily obfuscated and does not provide direct textual clues, but the heuristic firings strongly indicate a link farm used for malicious purposes.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9993

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://www.frontiermea.com/sites/all/libraries/ckfinder/userfiles/files/nazadiwidosisugav.pdf In PDF document text
    • http://inter-travel.hu/_user/file/60087301073.pdfIn PDF document text
    • http://interface-referencement.com/userfiles/file/39107805700.pdfIn PDF document text
    • https://hostessima.pl/userfiles/file/10418605560.pdfIn PDF document text
    • https://elsadaulte.com/ckfinder/userfiles/files/jeziwitabetapowi.pdfIn PDF document text
    • https://www.mysmilestudios.com/wp-content/plugins/super-forms/uploads/php/files/8e65d4048d2b8cf385613244c5917495/27389461841.pdfIn PDF document text
    • https://www.isnb.co.uk/wp-content/plugins/super-forms/uploads/php/files/35876172d0e51e9f9ecfd283550eb051/muguwagoraloxigu.pdfIn PDF document text
    • https://zifu-tech.com/app/webroot/userfiles/files/64009071053.pdfIn PDF document text
    • http://goodwill.pl/userfiles/file/11792884422.pdfIn PDF document text
    • http://argra.rs/wp-content/plugins/formcraft/file-upload/server/content/files/1606d520ca3612---vikenavarinosunibekutopan.pdfIn PDF document text
    • http://roocenter.ru/upload/file/bajegerojepumoxu.pdfIn PDF document text
    • https://stcatherine.ac.ug/wp-content/plugins/formcraft/file-upload/server/content/files/1607121cd66f43---zusinifejuni.pdfIn PDF document text
    • http://jjkxmy.com/upload/files/202109020125401160.pdfIn PDF document text
    • http://www.leposeur.fr/site/upload/ckfinder/files/67243272465.pdfIn PDF document text
    • https://www.gsccn.it/wp-content/plugins/formcraft/file-upload/server/content/files/160c87da029685---jumeriwake.pdfIn PDF document text
    • https://artsketch.ru/wp-content/plugins/super-forms/uploads/php/files/57fded802b4d1dee648644a6e66f3a97/70705757561.pdfIn PDF document text
    • https://www.sacict.or.th/ckfinder/userfiles/files/masexukajunepiv.pdfIn PDF document text
    • http://quick-thailand.com/images/uploads/file/jalox.pdfIn PDF document text
    • https://dialogueinpraxis.net/files/docs/35618772302.pdfIn PDF document text
    • https://www.financedeclined.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/160b123f2902bd---bokafupaxipokigodinol.pdfIn PDF document text
    • https://dongytueduc.com/wp-content/plugins/super-forms/uploads/php/files/48nkitsilmfd1v7ma51sguuhhn/widuluvavagun.pdfIn PDF document text
    • http://stlukesfp.org/ckfinder/userfiles/files/59599469904.pdfIn PDF document text
    • https://cafepiolho.com/uploads/assets/xodarisedurizokopijezove.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/BvfzZFkJO3s/uplcv?utm_term=6+letter+words+that+end+in+arPDF 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_off0000ba8c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBA8C 16852 bytes
SHA-256: e213bc5b85d396ec69dbc8779bb4bb72479fbfef31661d0850cac987321be3aa
font_01_sfnt_off0000e613.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE613 10500 bytes
SHA-256: e51863f4dc10620ae1f83fc368710e60f9976fcae8f170a42154e93f701d3397
font_02_sfnt_off0000fdfd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFDFD 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1