Malicious PDF — malware analysis report

Static analysis result for SHA-256 cb91d1a1f48212d9…

MALICIOUS

PDF

129.4 KB Created: 2021-09-04 05:15:29 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: 63f2814b6a38781d7e089b8a4139dc30 SHA-1: 73593b671c6898712dadba5aba627e4986ac19ad SHA-256: cb91d1a1f48212d9fec8540ba273782ec13df0ed44c66d8354a45527e769317a
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous external links, many pointing to compromised or disposable domains, indicating a phishing or malware distribution attempt. The ClamAV detection and ML classifier strongly suggest malicious intent. While no scripts were explicitly extracted, the nature of the link farm and the presence of PDF-specific heuristics suggest it may leverage embedded JavaScript or exploit PDF vulnerabilities to redirect users to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9985

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://crysiq.ru/uplcv?utm_term=mtap+reviewer+for+grade+2+2017+with+answers+pdf PDF link annotation
    • https://xn--b8qxb801j.tw/upload/files/59797902310.pdfIn PDF document text
    • https://nothingbutsafetyglasses.com/userfiles/file/39029035769.pdfIn PDF document text
    • https://www.bountyvacation.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607f78ef491f1---jarifiwokuji.pdfIn PDF document text
    • http://bestforfishing.com/wp-content/plugins/super-forms/uploads/php/files/abdfb7d663f0f3ce981bdc81af523be6/11878604953.pdfIn PDF document text
    • https://xn--80aaaglcftt5alesfkk7f.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/453794c7473ad54f0f3d055f4105b074/70350431648.pdfIn PDF document text
    • https://ohligschlaeger-berger.de/wp-content/plugins/formcraft/file-upload/server/content/files/160bcf79b3e866---30408119320.pdfIn PDF document text
    • http://robwalker.net/fckupload/file/7523108549.pdfIn PDF document text
    • http://pensionpoint.cz/userfiles/files/5152129495.pdfIn PDF document text
    • http://sanitaerprofi.ch/fckeditor/editor/images/file/bovojipuwedawi.pdfIn PDF document text
    • https://balaji-technology.com/userfiles/file/lorazolap.pdfIn PDF document text
    • https://www.golaw.net/wp-content/plugins/formcraft/file-upload/server/content/files/160b9981846480---94723662407.pdfIn PDF document text
    • http://vasilii-orlov.fun/wp-content/plugins/super-forms/uploads/php/files/f23f2e50298dd2f6127755a0aee598cc/ziponedalazuduzunateje.pdfIn PDF document text
    • http://myphamasia.net/upload/files/venoxu.pdfIn PDF document text
    • https://fokusmedia.com/images/uploads/19024126062.pdfIn PDF document text
    • https://boumqueur-edition.com/upload/fckeditor/file/jofetenexi.pdfIn PDF document text
    • http://gospel-pour-100-voix.com/fichiers/newsletter/file/35865707033.pdfIn PDF document text
    • http://alrabbancapital.com/file/files/noruxew.pdfIn PDF document text
    • https://www.capitalroofingct.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609473c18a338---nomawapiziwurom.pdfIn PDF document text
    • http://xboxheerlen.nl/userfiles/file/duzewulekabagudonew.pdfIn PDF document text
    • https://lsp.od.ua/wp-content/plugins/super-forms/uploads/php/files/g743jja909e3cfrv9qucprcl33/89107206815.pdfIn PDF document text
    • http://www.pzkexie.com/up_files/file/16543532744.pdfIn PDF document text
    • http://evohome.pl/userfiles/file/44095112779.pdfIn PDF document text
    • https://victory-agency.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612c508e2d9a6---datitidumef.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_off00018ff3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x18FF3 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0001a805.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1A805 20380 bytes
SHA-256: c59817fd3a4c4f3deb49309a6a912fadfce4dfea1ed4f34ae6b6bb132643478b
font_02_sfnt_off0001dd43.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1DD43 11220 bytes
SHA-256: fd31790872081a99581ef463f1e7f1ba4f8d80c6365c1098bb40c399cd38c5b0