Malicious PDF — malware analysis report

Static analysis result for SHA-256 c7ac0585854cb5d2…

MALICIOUS

PDF

71.0 KB Created: 2021-10-01 08:52:24 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 5edd33547f06ad104f5d41081c0a8d97 SHA-1: b0a486c01367da973884684c53b3625242c26758 SHA-256: c7ac0585854cb5d28c4a2b87d9666a54ba5c38d1a89765c42a78d9795d5561f5
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs, many of which point to compromised WordPress sites or disposable hosting, suggesting a link farm designed to distribute malicious content or phish users. The ClamAV detection and ML classifier strongly indicate malicious intent, likely related to phishing or malware distribution. While no scripts were explicitly extracted, the PDF structure and URL patterns are consistent with techniques used to redirect users to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9947

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://kemxoi.vn/app/webroot/files/images/pages/files/lafopabatajowilejep.pdf
    • http://ttmplus.com/userfiles/files/83701224439.pdf
    • https://pianotuningdarwin.com/userfiles/files/36549260288.pdf
    • http://sor1310.com/userfiles/file/97349710133.pdf
    • http://nhanvietgroup.com/demo/xay-dung-tnx/upload/files/25349362756.pdf
    • http://chenruichem.com/upload/files/zixesutatizabebulowaji.pdf
    • https://ateneoarbonaida.com/wp-content/plugins/formcraft/file-upload/server/content/files/161447c3dcdfcf---41238068728.pdf
    • http://djpress.pl/Image/files/kepexu.pdf
    • http://hzxgdz.com/images/upload/File/gimaralupinorobasofaril.pdf
    • https://eminenceconstruction.ca/viking1/uploads/files/99264959814.pdf
    • http://sarahscupcakery.com/wp-content/plugins/formcraft/file-upload/server/content/files/1615296e0e0604---24472805713.pdf
    • http://prosefkuchare.cz/userfiles/67911203255.pdf
    • https://togeltop.net/contents/files/69352822047.pdf
    • https://shinaltd.ru/images/file/vilumebetaso.pdf
    • http://www.finanzanlagen-honorarberatung.de/wp-content/plugins/formcraft/file-upload/server/content/files/16155b17ec858e---lexebozit.pdf
    • http://vivaibonomo.it/userfiles/files/39918176289.pdf
    • http://dochoiotovn.com/uploads/userfiles/file/19877633247.pdf
    • http://kelakewangshangduchang.a9188.com/upload_files/art_files/files/20210927_100025.pdf
    • https://rmissio.pl/wp-content/plugins/formcraft/file-upload/server/content/files/161480a4f2942d---50982513842.pdf
    • http://accapierre.it/userfiles/files/79587757146.pdf
    • http://kachelofen-prommegger.at/veposibe.pdf
    • http://interroadholland.nl/userfiles/file/megejofeletoxunaka.pdf
    • http://racecross.com/upload/edito_fckeditor/file/94152523055.pdf
    • http://nhuaduongnhapkhauaz.org/upload/files/nakutopunimipo.pdf
    • http://gd-weimi.com/upfolder/e/files/20210911015304.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/6naE_Nh8_CY/uplcv?utm_term=ray+bradbury+i+sing+the+body+electric+pdf
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000b254.bin
27632ccefe14079dc42ff66ff1d68ed1438996aed74d57107f18848011ea71d9
pdf-font-stream PDF embedded font (sfnt) at offset 0xB254 16372 bytes
font_01_sfnt_off0000dbfa.bin
ed769cce18cec2a85fdcc9b916aa35313149913761a1d56350d76fc73bbdaa34
pdf-font-stream PDF embedded font (sfnt) at offset 0xDBFA 11296 bytes
font_02_sfnt_off0000f613.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xF613 16792 bytes