Malicious PDF — malware analysis report

Static analysis result for SHA-256 cb1da8c7dd235797…

MALICIOUS

PDF

86.0 KB Created: 2021-09-06 01:30:21 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: cd785ce7ccf5746219c0bcac412a803d SHA-1: 9a2aa8ab25b462e97bc57412a941a4fb1824a14b SHA-256: cb1da8c7dd2357972506c41615b6b27a2ee83060f7c525a1229da82453181594
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 compromised CMS upload directories, suggesting a phishing or malicious redirection attempt. The ML classifier and ClamAV detection strongly indicate malicious intent, likely to lure users to malicious sites or download further payloads. The document's structure as a link farm is a common tactic for distributing malware or conducting phishing campaigns.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9989

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 https://msr-hudsonproperties.com/wp-content/plugins/super-forms/uploads/php/files/288c8c40e8554f3084001db70b40be18/8826113634.pdf In PDF document text
    • https://ilcaminodaugo.it/file/23148182399.pdfIn PDF document text
    • https://socohoteldanang.com/uploads/image/files/22477255190.pdfIn PDF document text
    • https://www.diktu.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606da07049b30---mikovuzifelivurujabete.pdfIn PDF document text
    • https://prospr.fr/ckfinder/userfiles/files/58742412798.pdfIn PDF document text
    • https://aspirans.com/files/file/91301233904.pdfIn PDF document text
    • http://aiaato.com/FileData/ckfinder/files/20210702_B9CDB539D8EB0776.pdfIn PDF document text
    • https://infravoip.com/wp-content/plugins/super-forms/uploads/php/files/1b11e11dbb7bb69e37d61aa125ec2380/titifubafewebe.pdfIn PDF document text
    • https://arvikabc.com/images/uploadedimages/file/titovizufifumubogomo.pdfIn PDF document text
    • https://contabil-fiscal.ro/mm/file/12027795071.pdfIn PDF document text
    • https://klingende-zeder.de/wp-content/plugins/formcraft/file-upload/server/content/files/160790c3de3408---11503432702.pdfIn PDF document text
    • https://yuanfuconstruction.com/ckfinder/upload/files/nimudibezilaze.pdfIn PDF document text
    • http://amirafouad.com/uploaded_files/file/fojidukuk.pdfIn PDF document text
    • http://www.melloecastro.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606ca906ad083---40210268775.pdfIn PDF document text
    • http://www.onekaddy.com/wp-content/plugins/formcraft/file-upload/server/content/files/1610797afb000e---tovafavodemaru.pdfIn PDF document text
    • http://ahlhy.com/uploads/file/092104385530.pdfIn PDF document text
    • https://tatsolarlight.com/uploads/files/44304899066.pdfIn PDF document text
    • http://voxel-avocats.fr/uploads/file/senanaxofowusebuxafaw.pdfIn PDF document text
    • https://klingende-zeder.de/wp-content/plugins/formcraft/file-upload/server/content/files/16131cd3316607---kipebuxotimoju.pdfIn PDF document text
    • http://entryexpress.online/chapter_images/files/97950817997.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/3vuEKuznOb8/uplcv?utm_term=mit+computer+science+syllabus+pdfPDF 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_off0000eab0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEAB0 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off000102c2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x102C2 17572 bytes
SHA-256: fe2031875d78b278a9133833c4dad92e71fae384234c1f68e4d9edfb8da4d354
font_02_sfnt_off00013089.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13089 11128 bytes
SHA-256: 592c6e56c02977fbdd26e54dc992eb9eee823bc5bb181a3c61166e84bc6fada3