Malicious PDF — malware analysis report

Static analysis result for SHA-256 a4554ff1d3a4f652…

MALICIOUS

PDF

92.0 KB Created: 2021-09-06 13:19:27 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: 8e719b2b44b77a367ff33465cc3e5b78 SHA-1: 9d0e94e6762a0f39e97068d00426107d901e8447 SHA-256: a4554ff1d3a4f652a28a9552c752b0fd0fe0e4709903d5e8724aaf1f875ff4bb
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains a link farm pointing to multiple compromised WordPress sites, indicating a phishing or malware distribution attempt. The ML classifier and ClamAV detection strongly suggest malicious intent. Although no scripts were explicitly extracted, the nature of the link farm and the presence of external URIs suggest it is designed to redirect users to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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://krisoc.ru/uplcv?utm_term=espectrofotometr%C3%ADa+de+absorci%C3%B3n+at%C3%B3mica+pdf PDF link annotation
    • http://ganan10.co.il/wp-content/plugins/formcraft/file-upload/server/content/files/160deb8613c68d---xagozenajizuvodipub.pdfIn PDF document text
    • http://jaika.in/images/documents/files/vofabiwolufagawixumaz.pdfIn PDF document text
    • https://designcoordinators.com/wp-content/plugins/formcraft/file-upload/server/content/files/160737a7800673---jujatovo.pdfIn PDF document text
    • http://africanhairbraidingsalon.com/userfiles/file/79754574544.pdfIn PDF document text
    • https://advicezone.org.uk/wp-content/plugins/super-forms/uploads/php/files/vklq33mbe5fvh6a2b8uil5qkd2/14613729324.pdfIn PDF document text
    • https://divorcioconsensual.com.br/wp-content/plugins/super-forms/uploads/php/files/f3450af05d374eb757e23d5c6120ba50/17804095419.pdfIn PDF document text
    • https://carthink.org/wp-content/plugins/formcraft/file-upload/server/content/files/1609f9751e8040---45424822266.pdfIn PDF document text
    • https://personalloan2u.com/wp-content/plugins/super-forms/uploads/php/files/8668ca9d7a3ff98600853326c2b24398/48994726313.pdfIn PDF document text
    • http://fred-robin.com/ckfinder/userfiles/files/verogewinoribisinepo.pdfIn PDF document text
    • http://soul-program.com/clients/e/e8/e84723a0d254fbc5507aaa4bd1967541/File/mavaxutitafowosinepapiwux.pdfIn PDF document text
    • http://accronline.com/userfiles/file/87000508420.pdfIn PDF document text
    • http://yanarfabrics.com/firma/files/10600815470.pdfIn PDF document text
    • http://alisawedding.com/upload/users/files/fibivaxofosutuzaponawisil.pdfIn PDF document text
    • https://sarujiovalente.com/wp-content/plugins/super-forms/uploads/php/files/qtc9qodomqeepcnbutam3oufb2/lelosudat.pdfIn PDF document text
    • http://yuseigachi.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1612f0e23ca676---nagitesix.pdfIn PDF document text
    • https://lsp.od.ua/wp-content/plugins/super-forms/uploads/php/files/4b6lldi7prob5fstv3ih5dvg16/80410760199.pdfIn PDF document text
    • http://gr-chem.com/upload/files/38766581047.pdfIn PDF document text
    • https://www.lowdoc-loans.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/160b5cefda1b20---wefivutisosegobolo.pdfIn PDF document text
    • http://philipwillettelaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/kubotizotigewudi.pdfIn PDF document text
    • http://www.orarestauratorisaf.it/wp-content/plugins/formcraft/file-upload/server/content/files/16072a5468534c---kusisuxezera.pdfIn PDF document text
    • http://webelievedin1984.com/clients/6/67/676624d6593aa512bfa6e10e765af00e/File/novesulanix.pdfIn PDF document text
    • http://joshuadacosta.com/wp-content/plugins/formcraft/file-upload/server/content/files/160be69f0aa4f2---95578378795.pdfIn PDF document text
    • https://www.nestroots.com/wp-content/plugins/super-forms/uploads/php/files/tdkij57cpi3nie4ooas783l533/27454815077.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_off0000fc1e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFC1E 11056 bytes
SHA-256: 6bb646513c5aa6c0d7bf2520102092ec2117910b70c5997ed32590c7a3108a3c
font_01_sfnt_off00011553.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11553 19568 bytes
SHA-256: 501f03646b8e4a269fe952b5dbc2259c4ee792819ec7d5946c2cc9b49a38670e
font_02_sfnt_off00014796.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x14796 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1