Malicious PDF — malware analysis report

Static analysis result for SHA-256 908730a37b0c9cbc…

MALICIOUS

PDF

76.8 KB Created: 2021-09-02 09:00:42 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: ef9ac6fa5504acfc2c1e83b45e2bdffc SHA-1: 3346cda483442268e5e9335fdd5d4c9f13c3d814 SHA-256: 908730a37b0c9cbccc5b46e9c91fe3bfea295ddf9909e774a8604fedd66d8ca1
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF file was flagged by multiple heuristics and a machine learning classifier as malicious, with ClamAV identifying it as a phishing trojan. It contains a link farm pointing to numerous URLs, many of which are hosted on compromised WordPress sites, suggesting an attempt to lure users to malicious content or phishing pages. No scripts were extracted, but the structure and URL distribution strongly indicate a malicious intent to redirect users.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9992

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://hieuchuan.com/upload/files/maxefefu.pdf In PDF document text
    • https://israelonthehouse.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b832b0f2783---firemu.pdfIn PDF document text
    • http://dush-kz.ru/uploads/fck/file/3223250190.pdfIn PDF document text
    • https://gtsonline.nl/wp-content/plugins/super-forms/uploads/php/files/4krdm25v6bobva50v4afp28t60/38627341431.pdfIn PDF document text
    • https://rpitrade.com/ckfinder/userfiles/files/joluvaruv.pdfIn PDF document text
    • https://www.hospedeagora.com.br/wp-content/plugins/super-forms/uploads/php/files/ga1kr0hcrom8hlbh60nd4pf66g/purepijeluzewojitiveralip.pdfIn PDF document text
    • http://rufullthrottle.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607757a4186e0---40897569585.pdfIn PDF document text
    • http://ulv-fogger.ru/d/files/gopoxanunovudukotijowoka.pdfIn PDF document text
    • https://danielstrehlau.com/userfiles/file/1908629369.pdfIn PDF document text
    • http://ordineveterinarivenezia.eu/userfiles/files/68815926003.pdfIn PDF document text
    • https://www.lorenzofranzone.it/wp-content/plugins/super-forms/uploads/php/files/f1c34c802a43f830419a7349c33a9954/wuvimemekewe.pdfIn PDF document text
    • https://naucharts.com/ckfinder/userfiles/files/fulupukavizag.pdfIn PDF document text
    • https://markzone.az/wp-content/plugins/super-forms/uploads/php/files/r1gegfkhto1td77odvu5hp5m20/99627720314.pdfIn PDF document text
    • http://pnmanagementsolutions.in/uploads/kufefuker.pdfIn PDF document text
    • http://poornasreehomeoclinic.com/ckfinder/userfiles/files/58938823478.pdfIn PDF document text
    • https://fid-data.fr/app/webroot/uploaderfiles/76199949570.pdfIn PDF document text
    • http://www.airportlimofortlauderdale.net/wp-content/plugins/formcraft/file-upload/server/content/files/160b85303f1418---savidedovijinodovilodor.pdfIn PDF document text
    • http://studioingegneramato.com/userfiles/files/83551530928.pdfIn PDF document text
    • http://tasteofruraleurope.eu/upload/File/jinadisesode.pdfIn PDF document text
    • https://csam-villepinte.org/uploads/images/file/44738302362.pdfIn PDF document text
    • http://www.colegiometa.net/home/wp-content/plugins/formcraft/file-upload/server/content/files/1607c317043d80---2828417244.pdfIn PDF document text
    • https://thetitangroup.ca/wp-content/plugins/super-forms/uploads/php/files/db40959ad4f16bc91f4aafb74a4e7c60/7055246698.pdfIn PDF document text
    • https://www.kadinlarsitesi.org/wp-content/plugins/formcraft/file-upload/server/content/files/16095f832332a3---musexuxobatud.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/FevRqgeaUVY/uplcv?utm_term=lung+cancer+metastasis+to+liver+life+expectancyPDF 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_off0000c98e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC98E 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000e1a0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE1A0 15992 bytes
SHA-256: a2db7679ce9b70a89ac6bc56e94494c2315adae7f4344381c61ec785ff8b0483
font_02_sfnt_off00010a85.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10A85 11160 bytes
SHA-256: c60d3df8158ec65d7a411a6bf05b6af979952a0e0842f4aca8303f14f014bfea