Malicious PDF — malware analysis report

Static analysis result for SHA-256 8251092161311897…

MALICIOUS

PDF

95.8 KB Created: 2021-09-19 14:10:43 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: ccd3646535c9477e8d54b9d261edfe40 SHA-1: 779358da439f278a26b49e8564e622577914e213 SHA-256: 82510921613118975413830ec75670acdd8d5f222356dff50e08c71c2e2ec24f
156 Risk Score

Malware Insights

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

The PDF contains numerous links, many pointing to disposable hosting or potentially compromised CMS upload directories, indicating a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely related to phishing or malware distribution. No scripts were extracted, but the structure and URL analysis point to a spearphishing attachment used to lure victims to external malicious sites.

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 http://qamsar.org/userfiles/files/vigisibura.pdf In PDF document text
    • https://brakos.it/file/podubasatewenokinigameju.pdfIn PDF document text
    • https://autonoleggioassereto.com/file/14671754527.pdfIn PDF document text
    • http://china-miyaco.com/img/file/2021930156.pdfIn PDF document text
    • http://bimbrlata.cz/UserFiles/File/pabosatabow.pdfIn PDF document text
    • http://classicalgardenstatues.com/uplds/file/jositanagevix.pdfIn PDF document text
    • https://maciejabramowicz.pl/upload/files/file/28892269303.pdfIn PDF document text
    • http://historico.uts.edu.co/portal/app/ckfinder/userfiles/files/deziwugaxunumod.pdfIn PDF document text
    • https://apelhijau.com/contents/files/84985526879.pdfIn PDF document text
    • https://www.lesson-online.org/wp-content/plugins/super-forms/uploads/php/files/bnbj0okbu6eqjh271c5dftrss6/18488989926.pdfIn PDF document text
    • http://ambvetsanprospero.eu/userfiles/files/8125907591.pdfIn PDF document text
    • https://lorus.rs/files/wovitezoniwer.pdfIn PDF document text
    • http://vendsol.com/userfiles/file/58529733525.pdfIn PDF document text
    • https://varbackaforskola.se/ckfinder/userfiles/files/durub.pdfIn PDF document text
    • https://gift-edu.ru/wp-content/plugins/super-forms/uploads/php/files/d702eee3c284374fdb3952b5d8a543e7/91212547046.pdfIn PDF document text
    • http://www.bash.cl/media/file/vimosa.pdfIn PDF document text
    • http://wwpokebar.com/uploads/files/fepoleribugaw.pdfIn PDF document text
    • https://www.chauffeur-prive-nice.fr/wp-content/plugins/formcraft/file-upload/server/content/files/16141fa4aac0e0---xulexetuposikurepokitasi.pdfIn PDF document text
    • http://nprofit.hk/userfiles/85740508447.pdfIn PDF document text
    • http://simoncaulkin.com/images/62799937506.pdfIn PDF document text
    • http://impex-italia.it/userfiles/files/94562495143.pdfIn PDF document text
    • http://acupunctuuryao.nl/ckfinder/userfiles/files/90097856138.pdfIn PDF document text
    • https://ost-fogging.com/upload/files/zanexujekevepijaz.pdfIn PDF document text
    • http://telecycling.info/files/file/28049342978.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/cv9VXjIrmdE/uplcv?utm_term=best+horror+films+2021PDF 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_off00010e87.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10E87 19444 bytes
SHA-256: 7adecc7e50751d44c60cd7ce038db878dd451e3535ea97ca9d91482586e45fe1
font_01_sfnt_off00014158.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x14158 10560 bytes
SHA-256: 17f803f98431a29998e813ba2caabdca2cd7ba5b493f7245d247cd8c6471d66b
font_02_sfnt_off00015987.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x15987 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1