Malicious PDF — malware analysis report

Static analysis result for SHA-256 4fc3d7a96e0a3abe…

MALICIOUS

PDF

79.7 KB Created: 2021-09-07 12:52:54 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-31
MD5: c5f758e586126b7f0cfa15414ba01e35 SHA-1: bfa54fdf978ded62cdc3133fcdb1057dbb2c814a SHA-256: 4fc3d7a96e0a3abe5a9079050e8515b670932301bc542350dda36d79debdf5b0
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF contains numerous links, many pointing to potentially compromised WordPress sites hosting other PDF files. This behavior is characteristic of a link farm used to distribute malicious content or conduct phishing attacks. The ML classifier and ClamAV detection strongly indicate malicious intent, likely related to phishing or malware delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9991

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://www.rec39.ru/wp-content/plugins/super-forms/uploads/php/files/565da778a33748328fd38d9d1efb0d54/dazufigabuvudo.pdf In PDF document text
    • http://urparitet.ru/admin/ckfinder/userfiles/files/zolasukifufifelesapomuj.pdfIn PDF document text
    • http://www.caribbeandentist.com/wp-content/plugins/formcraft/file-upload/server/content/files/160811d9781a53---bugapuw.pdfIn PDF document text
    • http://anatolianlgs.com/userfiles/file/jijegis.pdfIn PDF document text
    • http://www.farparts.cl/wp-content/plugins/formcraft/file-upload/server/content/files/1608d260f9f24e---korovujuni.pdfIn PDF document text
    • http://fli.edu.mn/ckfinder/userfiles/files/kunoguwekorawujaliv.pdfIn PDF document text
    • http://csc-028.com/userfiles/file/20210721191321_90lg6h.pdfIn PDF document text
    • http://www.maoles.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607d92025486b---83689836008.pdfIn PDF document text
    • http://pusulacampeyzaj.com/images/media/files/40821664291.pdfIn PDF document text
    • https://agrimal.pl/userfiles/file/44958299357.pdfIn PDF document text
    • http://shahnawazonline.com/uploads/files/3611399461.pdfIn PDF document text
    • https://mamproducciones.es/wp-content/plugins/formcraft/file-upload/server/content/files/160bad5a28a89e---nubozibidufu.pdfIn PDF document text
    • https://asthasupermarket.com/userfiles/file/28786158087.pdfIn PDF document text
    • https://joepromenshealth.com/wp-content/plugins/super-forms/uploads/php/files/2798e161821e9040f7a0862d79906c98/80249317519.pdfIn PDF document text
    • http://unipsyclinic.com/userfiles/file/20210607132459.pdfIn PDF document text
    • https://benchmarktransitions.com/wp-content/plugins/formcraft/file-upload/server/content/files/16079c25180bde---nefizap.pdfIn PDF document text
    • http://www.kindytennis.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608210298c415---lixetaki.pdfIn PDF document text
    • http://hookmyweddingup.net/clients/73542/File/xeludeminetagetewiz.pdfIn PDF document text
    • http://watthaistuttgart.de/userfiles/file/54533945152.pdfIn PDF document text
    • http://chinhsuasolieu.com/media/files/fubixadujawexepemib.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/1KS0DP0cxss/uplcv?utm_term=skullcandy+wireless+headphones+instruction+manualPDF 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_off0000d026.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD026 17936 bytes
SHA-256: 050797ecda626e07b315957c9af5d8bb2e53f5f0684bc0e04807bb9fe71ee934
font_01_sfnt_off0000fea5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFEA5 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000116bc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x116BC 11244 bytes
SHA-256: c25c7606c309e02d2b206c34183d978a6bc97e7628af7721860621c9be77103f