Malicious PDF — malware analysis report

Static analysis result for SHA-256 c81a5b7651affe2b…

MALICIOUS

PDF

93.6 KB Created: 2021-09-05 03:13:08 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 3f777f9cab8928c70cbfa3b71c32d59b SHA-1: 8a93b10363bd22200bda9a48d2835236ba8d0088 SHA-256: c81a5b7651affe2ba994956abad51ff6cf942520a78bb4d21df765bb90da7c94
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF contains numerous embedded URLs, many pointing to compromised or disposable hosting, indicative of a link farm designed to redirect users to malicious sites. The ML classifier and ClamAV detection strongly suggest malicious intent, likely phishing or malware delivery. The PDF_SEO_DISPOSABLE_LINK_FARM heuristic further supports the nature of the document as a link farm.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9822

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://campermagazine.tv/public/file/xeparevobewevezixibogoxeg.pdf In PDF document text
    • https://israelonthehouse.com/wp-content/plugins/formcraft/file-upload/server/content/files/160db3821e446f---dokiluvekitage.pdfIn PDF document text
    • https://kabelkyaobuv.sk/editor_uploads/files/widinava.pdfIn PDF document text
    • https://nusantarabet4d1.com/contents//files/41259366380.pdfIn PDF document text
    • http://tugrabilgisayar.net/resimler/files/dedifuxanobukuma.pdfIn PDF document text
    • https://ktmcollege.org/public_html/userfiles/file/futojugakel.pdfIn PDF document text
    • http://alrabbancapital.com/file/files/3843201078.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/16085658f19d5f---44601961039.pdfIn PDF document text
    • http://xn--80age2amlc.xn--80adxhks/pics/images/file/xujukugaranomabojiloz.pdfIn PDF document text
    • https://sodigital.it/wp-content/plugins/formcraft/file-upload/server/content/files/16112863e279f2---94298646975.pdfIn PDF document text
    • http://luckyassessoria.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1608a5102db2fe---vemixegewepezak.pdfIn PDF document text
    • http://www.peplex.it/wp-content/plugins/formcraft/file-upload/server/content/files/1607bdd1961367---56196994606.pdfIn PDF document text
    • http://sinara.org.br/wp-content/plugins/formcraft/file-upload/server/content/files/16077a12b31c2e---rarixeve.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bf9be968a20---7475348939.pdfIn PDF document text
    • http://recamonde.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160ae7ee90f2ae---bivanimewekewujabupit.pdfIn PDF document text
    • https://doctornhospital.com/banglanews24/editorsfiles/files/kudoso.pdfIn PDF document text
    • http://posicert.com/upload_fck/file/2021-9-4/20210904210404387620.pdfIn PDF document text
    • https://guclupin.com/calisma2/files/uploads/95188356033.pdfIn PDF document text
    • http://www.recetasyconsejos.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b5495461015---xebelulakafon.pdfIn PDF document text
    • https://ferado.vn/userfiles/file/jinafopomipuze.pdfIn PDF document text
    • http://hookmyweddingup.net/clients/73542/File/dofew.pdfIn PDF document text
    • http://qctc.vn/upload/files/tipalikubobor.pdfIn PDF document text
    • https://www.surajinformatics.com/wp-content/plugins/super-forms/uploads/php/files/05a7c8531f14e55bf5def4a2771810dc/55180158368.pdfIn PDF document text
    • http://alvasari.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607d3cec2fe31---84131480633.pdfIn PDF document text
    • http://drairtools.com/ckfinder/userfiles/files/82812725815.pdfIn PDF document text
    • http://simpelms.nl/userfiles//files/wumejerepixurekubafid.pdfIn PDF document text
    • https://bentzendesign.se/wp-content/plugins/formcraft/file-upload/server/content/files/1607bb5ab3552b---gepukale.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/GLLx1DTH0VQ/uplcv?utm_term=tr%E1%BB%8Dng+sinh+chi+%C3%B4n+uy%E1%BB%83n+pdfPDF 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_off0000fcc5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFCC5 28624 bytes
SHA-256: b4e6096e2bb7c4f57a7c1c6fc06a31fc970e464a532e4ef731d99449f519e436
font_01_sfnt_off0001358c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1358C 11064 bytes
SHA-256: 54bc37d947814ef5794b708e8f8f0100d52aad9134d5e9e1a2e3634c56e9d002
font_02_sfnt_off00014ed3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x14ED3 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1