Malicious PDF — malware analysis report

Static analysis result for SHA-256 28f9faf161c33e3a…

MALICIOUS

PDF

70.0 KB Created: 2021-09-14 09:42:51 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 633e52e3e51409e0698e91838463a488 SHA-1: f6bcb79490306ab160b642e479809a40a84e2747 SHA-256: 28f9faf161c33e3ac610b8c444ab9fd976793d554f35c55dec5ce5a3d8d5e106
156 Risk Score

Malware Insights

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

The PDF contains numerous external URIs and is identified as a link farm, with many links pointing to other PDF files hosted on various domains. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or distributing further malware. The presence of multiple external links and the 'link farm' heuristic suggest an attempt to obscure the ultimate destination or to host a collection of malicious documents.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9965

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://pixomot.ru/uplcv?utm_term=printable+d%26d+miniatures+pdf PDF link annotation
    • http://vendax.ro/files/file/76938676658.pdfIn PDF document text
    • https://e-fasteners.eu/media/file/xunokivugosowesodezube.pdfIn PDF document text
    • http://thsport.dk/ckfinder/userfiles/files/xoparagujiwivutulil.pdfIn PDF document text
    • https://prevodi-plovdiv.com/userfiles/file/97784089093.pdfIn PDF document text
    • http://studioagronomoserragiotto.eu/userfiles/files/179433651.pdfIn PDF document text
    • http://chiaranannini.com/userfiles/files/15791626403.pdfIn PDF document text
    • http://cgpharma.in/cote_dor_import/admin/ckfinder/userfiles/files/61533084707.pdfIn PDF document text
    • https://juhaszautovill.hu/userfiles/file/67940327488.pdfIn PDF document text
    • https://sproname.com/files/userfiles/files/82808900541.pdfIn PDF document text
    • https://feriaesotericadeatocha.com/wp-content/plugins/formcraft/file-upload/server/content/files/161376d3dd9ad9---65124495310.pdfIn PDF document text
    • http://somsit.com/ckfinder/userfiles/files/66929069694.pdfIn PDF document text
    • http://puisan.ru/uploads/file/47665872377.pdfIn PDF document text
    • http://airmon.hu/images/files/27636373783.pdfIn PDF document text
    • http://www.marsagri.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613a0f2db0b28---55045060412.pdfIn PDF document text
    • http://hemeringen.de/ckeditor_ablage/userfiles/files/98541616063.pdfIn PDF document text
    • https://priscar.com/documents/files/verur.pdfIn PDF document text
    • https://www.cukoyem.com.tr/wp-content/plugins/super-forms/uploads/php/files/86io8krd024968ua8brgnjeba5/jodasijuzawuje.pdfIn PDF document text
    • http://billsky.ee/files/file/bajabadat.pdfIn PDF document text
    • https://xlspandoek.nl/userfiles/file/42173921406.pdfIn PDF document text
    • http://zoltysnieg.pl/pliki_wyswig/files/24239633078.pdfIn PDF document text
    • http://heninrealty.com/userfiles/files/fepuki.pdfIn PDF document text
    • http://gillsandgeckos.com/userfiles/file/viresomefebogod.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_off0000b249.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB249 16400 bytes
SHA-256: 76fdd5abebe8ab2b2542d4645e36eebfd9f60c6fcad2f943d02a3bd125e0417a
font_01_sfnt_off0000dc71.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDC71 10096 bytes
SHA-256: b61092477582a79104b7a9a4452e2b9d38c175fd975ba13eea3b402004fcad66
font_02_sfnt_off0000f2fe.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF2FE 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1