Malicious PDF — malware analysis report

Static analysis result for SHA-256 6ac37f22a959d8a6…

MALICIOUS

PDF

71.2 KB Created: 2021-09-05 10:19:07 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: 6ab23ecbbc8ebdbc7d27f40d0effbbae SHA-1: d6b0709f1fe9172e1568cfead7ee0e14d6f48250 SHA-256: 6ac37f22a959d8a62ad57a0dd1c9a6da8604852845f5909115ac3702e6e69bf9
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs, many pointing to compromised WordPress sites, suggesting a link farm designed to redirect users to malicious content. The ClamAV detection and ML classifier strongly indicate malicious intent, likely for phishing or malware distribution. No scripts were extracted, but the presence of external links is a primary indicator of malicious activity.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9991

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://chcial.ru/uplcv?utm_term=understanding+sociology+class+11+pdf PDF link annotation
    • http://grupogmec.com/wp-content/plugins/formcraft/file-upload/server/content/files/160907215235a3---61967579691.pdfIn PDF document text
    • https://baodinhsolar.com/wp-content/plugins/super-forms/uploads/php/files/ob6uol2udv2gb9tmsd5tt29t5g/41590255956.pdfIn PDF document text
    • http://duda-tech.pl/dudatech/upload/file/4299281349.pdfIn PDF document text
    • http://ligneus.hu/upload/file/99609829493.pdfIn PDF document text
    • http://www.holderit.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608d262ce9404---wazevuvujisomubozadiporav.pdfIn PDF document text
    • https://www.cukoyem.com.tr/wp-content/plugins/super-forms/uploads/php/files/0do078a73gf784v8r4ufgldm92/4696448013.pdfIn PDF document text
    • http://yh-nutri.com/filespath/files/20210902012342.pdfIn PDF document text
    • http://iburgisidimarsala.eu/userfiles/files/puwizafowofozovuroguwa.pdfIn PDF document text
    • http://strahovka66.ru/userfiles/file/leligajufogaselo.pdfIn PDF document text
    • http://www.me.ntou.edu.tw/ckfinder/userfiles/files/20210811_093302.pdfIn PDF document text
    • http://amunt.madteam.net/ckfinder/userfiles/files/17820617916.pdfIn PDF document text
    • https://psfund.org/public/uploads/files/cms_files/17087180990.pdfIn PDF document text
    • http://maasmartcity.com/userfiles/file/jomumave.pdfIn PDF document text
    • https://swagath.co/new/ckfinder/userfiles/files/gobowafalevurepar.pdfIn PDF document text
    • http://elitvorota.ru/f/file/zulotuwure.pdfIn PDF document text
    • http://www.medicellbank.com/userfiles/files/67260909910.pdfIn PDF document text
    • http://mijneigenlift.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1610386fd336ce---74623843870.pdfIn PDF document text
    • http://theettiaresottawa.ca/clients/e/e8/e8f54e69a7463df9fd0adff13cd8e90f/File/pumesa.pdfIn PDF document text
    • http://archimax.ch/dynamic-images/cms/file/metaxejurog.pdfIn PDF document text
    • http://tzoetemondje.be/uploads/files/20899074840.pdfIn 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://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_off0000b2da.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB2DA 10968 bytes
SHA-256: c8fdd2f6f580a5a93e61c389f4ff1b83fb420d2d47696df3e98b2a0353e1d9f9
font_01_sfnt_off0000cc47.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCC47 16716 bytes
SHA-256: 823ff90f2e8c34dca3e58caf1627e6d464aa346c5714e84ecd44e8c52e425363
font_02_sfnt_off0000f7a6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF7A6 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1