Malicious PDF — malware analysis report

Static analysis result for SHA-256 3b5a7e81b668659d…

MALICIOUS

PDF

68.1 KB Created: 2021-10-03 15:05:14 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 4caba47e8ddaa37c74f9500031a3d692 SHA-1: 138ae76d253ed30bd4a14b622e6797dfc81c846c SHA-256: 3b5a7e81b668659d8f07bb81755c961372c6f6e6836a4fdd12742d829aea135c
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs, many pointing to compromised WordPress sites, suggesting a link farm designed to redirect users to malicious content. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or malware distribution. Although no scripts were explicitly extracted, the PDF structure and URL patterns are consistent with techniques used to host malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9957

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://oniceh.ru/uplcv?utm_term=what+to+do+for+a+torn+ligament PDF link annotation
    • https://www.a2zmedical.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/16141b6e48e403---68457808155.pdfIn PDF document text
    • https://www.sevgiliyevideo.net/wp-content/plugins/formcraft/file-upload/server/content/files/1614047e0c160a---viminewonamef.pdfIn PDF document text
    • http://mojaksiegowa.net/userfiles/file/femovibezexamulenifegaj.pdfIn PDF document text
    • https://hoongnau.com/upload/files/47908122758.pdfIn PDF document text
    • http://anhuizpyy.com/upload_fck/file/2021-9-19/20210919015809170797.pdfIn PDF document text
    • https://tocgia247.com/wp-content/plugins/super-forms/uploads/php/files/re8i7ip3pd7cv6mm0p772j3kl6/41892870778.pdfIn PDF document text
    • https://taumed.kz/upload/2021/09files/2109092228540963036m277.pdfIn PDF document text
    • http://www.santabriganti.org/admin/ckfinder/userfiles/files/86537185452.pdfIn PDF document text
    • http://support-cmu.com/filedata/file/68661297589.pdfIn PDF document text
    • http://internet-trade.cz/UserFiles/file/83066724586.pdfIn PDF document text
    • http://greenworx.eu/images/uploads/files/duriwejesit.pdfIn PDF document text
    • http://dongshengcable.com/images/upload/File/97024263071.pdfIn PDF document text
    • https://hazeloyun.com/calisma2/files/uploads/vuruf.pdfIn PDF document text
    • http://parateam.cz/file/movuvul.pdfIn PDF document text
    • http://lapawan15.com/shop/fck_file/file/4009830729.pdfIn PDF document text
    • http://www.patricktennis.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1614d0aa84da7a---buwibipaviresizuwonarig.pdfIn PDF document text
    • http://salman-group.com/userfiles/file/lepomifoxufe.pdfIn PDF document text
    • http://odpadykj.cz/UserFiles/File/88084077073.pdfIn PDF document text
    • https://bilalyapidekorasyon.com/userfiles/file/68462226380.pdfIn PDF document text
    • https://sayurmateng.com/contents/files/sufunip.pdfIn PDF document text
    • http://www.tiande-global.com/ckfinder/userfiles/files/fetogovizon.pdfIn PDF document text
    • http://myesen.life/userfiles/file/niganuvebamod.pdfIn PDF document text
    • https://afraitn.com/basefile/afra/files/35648639914.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_off0000ae1c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xAE1C 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000c633.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC633 10628 bytes
SHA-256: 87b389551461c33c960d684fe22c18fb010b82859a4e21ae32ee8b4fac6c91b2
font_02_sfnt_off0000de14.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDE14 14756 bytes
SHA-256: a4899173a3d2fc3ef2ca1b96a8a3e65d97dd3a5fc045b37057960ca3604864c5