Malicious PDF — malware analysis report

Static analysis result for SHA-256 d63d9b21750cc51f…

MALICIOUS

PDF

84.2 KB Created: 2021-09-13 09:53:45 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 3ef43950f94d5106f940b40e112a02bd SHA-1: cf00d9943287084a92095f787b70f3c93f649f98 SHA-256: d63d9b21750cc51f0c0502bb3f45b985df479f4db149e2672234790126e72c5e
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.001 User Execution: Malicious Link

The PDF file was flagged by multiple heuristics as malicious, including a ML classifier and ClamAV, indicating a high likelihood of malicious intent. The presence of numerous external URIs, many pointing to potentially compromised or disposable hosting, suggests a link farm designed to redirect users to malicious content. The document body is heavily obfuscated, preventing a clear understanding of its specific lure, but the overall structure and URL analysis point towards a phishing or malware distribution scheme.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9955

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 http://studiogallerani.it/userfiles/files/97224713496.pdf In PDF document text
    • http://eugensa.lt/app/webroot/uploads/userfiles/files/90073349498.pdfIn PDF document text
    • https://manhremhoangvan.vn/wp-content/uploads/files/40249513398.pdfIn PDF document text
    • http://s8radziejowice-paszkow.pl/userfiles/file/takafipafopojaf.pdfIn PDF document text
    • http://rivebistro.net/ckfinder/userfiles/files/23100304652.pdfIn PDF document text
    • https://vkgnassociates.com/dayafter/uploadimages/newsimages/file/80592127262.pdfIn PDF document text
    • http://kemmurad.com/webroot/img/files/85473936699.pdfIn PDF document text
    • http://biondiairsystem.it/userfiles/files/xedij.pdfIn PDF document text
    • http://4998horo.gmmwireless.com/contents/files/jutelitufizaxejoz.pdfIn PDF document text
    • http://finsura-lifedirect.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/1612eec6316256---31458220471.pdfIn PDF document text
    • http://hotelbellevuepalermo.com/userfiles/files/sobom.pdfIn PDF document text
    • https://biserica-izvorul-tamaduirii.ro/files/78978700100.pdfIn PDF document text
    • http://pincesorvarshop.hu/editor_up/zulofomokojimidox.pdfIn PDF document text
    • https://ubk-sad.de/azubi/userfiles/files/12750321412.pdfIn PDF document text
    • http://ktcz.eu/files/files/30280802519.pdfIn PDF document text
    • http://studiolorenzino.eu/userfiles/files/41423403208.pdfIn PDF document text
    • http://gabinetpro.gabinetpro.pl/kosmetyczka/krakow/files/90737014577.pdfIn PDF document text
    • http://compsult.net/userfiles/file/fexunibuzinigebaz.pdfIn PDF document text
    • https://www.ferienhof-schneider.de/wp-content/plugins/formcraft/file-upload/server/content/files/1613aad950883c---nevewobijofezetapisab.pdfIn PDF document text
    • http://trainternational.in/wp-content/plugins/formcraft/file-upload/server/content/files/16132bae321752---92406743709.pdfIn PDF document text
    • http://bimbrlata.cz/UserFiles/File/47606483708.pdfIn PDF document text
    • http://www.malagatour.es/ckfinder/userfiles/files/5225574320.pdfIn PDF document text
    • http://fotosvatba.net/userfiles/file/84278103585.pdfIn PDF document text
    • https://ecableapp.com/FCKeditor/FCKimgUpload/file/49699319872.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/YTWXjIUwRh0/uplcv?utm_term=nerves+in+chest+and+armPDF 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_off0000e75f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE75F 10512 bytes
SHA-256: 9e6520161f0a76a1409de4d6515e1a7940b7c958a4bba6b0d6fa5224558b943c
font_01_sfnt_off0000ff21.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFF21 17080 bytes
SHA-256: 23452788bed902d01b99635d40e12be4e15257af4643db6714f9e5a797aa0bf2
font_02_sfnt_off00012b89.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12B89 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1