Malicious PDF — malware analysis report

Static analysis result for SHA-256 cbdb768e456d7cc8…

MALICIOUS

PDF

70.4 KB Created: 2021-09-26 18:28:50 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-24
MD5: b43e6e6d620fa337edd7f3ea4f78f938 SHA-1: ff51d833eab88b0522b2443966e1de6bc1fd8fce SHA-256: cbdb768e456d7cc8cc25ad7d5400b5aa6a4606fcc9fafb4119ee6f4658169943
156 Risk Score

Malware Insights

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

The PDF was flagged by ML classifiers and ClamAV as malicious, indicating it likely exploits a vulnerability or contains malicious content. It contains numerous links to external websites, many hosted on compromised CMS platforms or disposable domains, suggesting a phishing or malware distribution lure. The presence of external URI heuristics and link farm patterns further supports this assessment.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9978

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://krisoc.ru/uplcv?utm_term=unturned+hmg+box PDF link annotation
    • http://korvet-sp.ru/userfiles/file/24671924068.pdfIn PDF document text
    • http://sxhk365.com/uploads/file///19388136351.pdfIn PDF document text
    • http://ginzaramen.us/uploads/files/18744577307.pdfIn PDF document text
    • http://pomelieagency.com/userfiles/files/39355139966.pdfIn PDF document text
    • http://studiostocchi.eu/userfiles/files/gafazatog.pdfIn PDF document text
    • http://adance0112.com/upfile/editor/file/14926500580.pdfIn PDF document text
    • https://schreinerheusi.de/wp-content/plugins/formcraft/file-upload/server/content/files/1614ad3c9ccf77---burifumol.pdfIn PDF document text
    • http://www.cascinasorigherio.it/wp-content/plugins/formcraft/file-upload/server/content/files/1614661cea5825---87992985242.pdfIn PDF document text
    • http://topup-fight.com/ckfinder/userfiles/files/30657008799.pdfIn PDF document text
    • http://mp-journal.com/media/file/donodanibomoxotarajagor.pdfIn PDF document text
    • http://nattukoottam.com/userfiles/file/53782585842.pdfIn PDF document text
    • http://www.sunarpazarlama.com/wp-content/plugins/super-forms/uploads/php/files/9dm6tr0o7o73gc0d4c92iag5h6/xilaminimakagatalofujem.pdfIn PDF document text
    • http://www.peritaonline.es/ckfinder/userfiles/files/gozuzapilibop.pdfIn PDF document text
    • http://zkmeiqi.com/admin/ckfinder/upfile/files/62086735058.pdfIn PDF document text
    • http://originalbau.hu/imagesfiles/25284405781.pdfIn PDF document text
    • https://ego-sofa.tw/uploads/files/202109241821083037.pdfIn PDF document text
    • http://hylimusic.com/fckeditor/editor/filemanager/connectors/php/userfiles/file/dedomibegitefuda.pdfIn PDF document text
    • https://samavetpharm.com/userfiles/files/38423751469.pdfIn PDF document text
    • https://eminencesolutions.in/resources/userfiles/file/zejunoguvu.pdfIn PDF document text
    • http://intechsol.kz/wp-content/plugins/formcraft/file-upload/server/content/files/1614e3479ce8cd---xiloluzusatimedi.pdfIn PDF document text
    • http://arndt-fahrschule.de/userfiles/file/52099944725.pdfIn PDF document text
    • http://londonjip.com/userData/board/file/denebiguko.pdfIn PDF document text
    • http://worldwidestationeryholdings.com/files/file/morasip.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_off0000b197.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB197 16764 bytes
SHA-256: 65151854c22292265dae9b928b7ef48f5fde7141b0ba95a8022a490e7a8c422d
font_01_sfnt_off0000dc18.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDC18 10576 bytes
SHA-256: 84dbe1634635d3ad9a62814a1a4a1194b89e2f9c51ea502e6d73de3ed6023557
font_02_sfnt_off0000f3ce.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF3CE 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1