Malicious PDF — malware analysis report

Static analysis result for SHA-256 3824d27c1bbb8841…

MALICIOUS

PDF

97.8 KB Created: 2021-09-19 18:52:30 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: d2c5582d969a576620c405467075d115 SHA-1: 2f4ad098c3dce2a4bdc77645095deaf19ad28714 SHA-256: 3824d27c1bbb8841ea1a25a331612f11eb25a5372c15e54813862fd5cabf3f46
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file was detected as malicious by ClamAV and an ML classifier, and exhibits characteristics of a link farm. Multiple heuristics indicate the PDF contains numerous external links, many hosted on potentially compromised or disposable domains, suggesting a phishing or malware distribution lure. The presence of embedded URLs further supports this, indicating the PDF's primary function is to redirect users to malicious external content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9875

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://cructi.ru/uplcv?utm_term=avg+mobile+security+review PDF link annotation
    • https://novinfasteners.com/userfiles/file/nirofebeni.pdfIn PDF document text
    • http://reiki-roots.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/1612f4382a97de---80052256522.pdfIn PDF document text
    • http://unseretochter.ch/images/file/fulokuwamilazu.pdfIn PDF document text
    • https://mimpishio1.com/contents/files/51885116665.pdfIn PDF document text
    • http://foxgraphics.paulsfashion.in/files/63939019634.pdfIn PDF document text
    • http://licausi.it/userfiles/files/vagasirefimu.pdfIn PDF document text
    • http://xn----dtbhwhggdaoqfh3d.xn--p1ai/media/file/vibakiseleb.pdfIn PDF document text
    • http://limobebe.com/userfiles/files/38093876980.pdfIn PDF document text
    • http://studiosantese.eu/userfiles/files/51595599622.pdfIn PDF document text
    • http://kleni.cz/userfiles/file/bufurogewaf.pdfIn PDF document text
    • https://unique.global/wp-content/plugins/super-forms/uploads/php/files/dae7facbfcb449e8578653fd33476c95/6636327155.pdfIn PDF document text
    • http://okvin.org/userfiles/file/66337436472.pdfIn PDF document text
    • http://taigesw.com/upload/files/vijoxuzakukekipe.pdfIn PDF document text
    • http://www.siscard.com/wp-content/plugins/formcraft/file-upload/server/content/files/16133844c1d66e---32778027264.pdfIn PDF document text
    • https://birsamundapark.in/userfiles/files/xedirepeme.pdfIn PDF document text
    • https://www.carlosfunes.es/wp-content/plugins/formcraft/file-upload/server/content/files/1613f88f1077d7---13832911795.pdfIn PDF document text
    • https://santehsevast.ru/userfiles/files/pakawodi.pdfIn PDF document text
    • https://szalkasszorutacskok.hu/app/webroot/files/content/files/64564771744.pdfIn PDF document text
    • https://petribax.nl/userfiles/file/besitosimubi.pdfIn PDF document text
    • http://okfilm.kr/userData/board/file/34247671950.pdfIn PDF document text
    • http://intrinhgia.com/admin/webroot/upload/image/files/96863239929.pdfIn PDF document text
    • http://cmrivestimenti.com/userfiles/files/94787985476.pdfIn PDF document text
    • http://loaamtran.vn/files/usersfiles/files/32527182587.pdfIn PDF document text
    • http://sor1310.com/userfiles/file/libisog.pdfIn PDF document text
    • http://locke-3c.tw/uploads/files/202109170128575987.pdfIn PDF document text
    • https://tedesco.pl/userfiles/file/gekarama.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_off000118a2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x118A2 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off000130b9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x130B9 10796 bytes
SHA-256: dd5ac8b68e23676bb195f26c31259e8336ce8c4c7af7aeb0157074db494487f6
font_02_sfnt_off000149bd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x149BD 18404 bytes
SHA-256: dc3a736e467458099cc6c4aa610308da7a85a88d094c65f7bfbf38c1c5567f53