Malicious PDF — malware analysis report

Static analysis result for SHA-256 a5f1b0938b70666c…

MALICIOUS

PDF

70.8 KB Created: 2021-09-27 20:44:10 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-23
MD5: e301f4fde35389049ba66f709d9853d3 SHA-1: 2a9b82f978fd41078ce537d5cd2d457123bb4ef7 SHA-256: a5f1b0938b70666c1f0beadd5b3fe53d1864ab2463524d25f2250f15d71a7813
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The ML classifier and ClamAV detection strongly indicate malicious intent. The PDF contains numerous links to distinct domains, many of which are likely disposable, suggesting a link farm used to obscure the ultimate destination or host malicious content. While no scripts were explicitly extracted, the PDF structure and heuristic firings point towards a phishing or malware distribution attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://rm-centr.ru/uploads/file/50251409601.pdf In PDF document text
    • https://1sis.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613252c993def---pavore.pdfIn PDF document text
    • http://amsasecretariat.fr/userfiles/file/4435120820.pdfIn PDF document text
    • http://yibetter.com/data/files/fodutanunokulafilikopix.pdfIn PDF document text
    • https://taperagi.com/contents/files/21867201888.pdfIn PDF document text
    • http://hkbroadwin.com/userfiles/54151313498.pdfIn PDF document text
    • http://lasantitosrestaurant.com/userfiles/file/90764308148.pdfIn PDF document text
    • https://myclubowners.travelenvogue.com/userfiles/files/jigasor.pdfIn PDF document text
    • http://medizator.ru/ckfinder/userfiles/files/nabipolopiruledupenosef.pdfIn PDF document text
    • http://klwas.org/userfiles/images/file/51925301044.pdfIn PDF document text
    • https://www.cdsale.org.au/application/third_party/ckfinder/userfiles/files/66023536310.pdfIn PDF document text
    • http://haliburtonhighlandsheritage.ca/userfiles/file/71875113931.pdfIn PDF document text
    • https://oferta.lt/i/File/desapigaworafurevu.pdfIn PDF document text
    • https://polytex.de/sites/default/files/46913841056.pdfIn PDF document text
    • http://glassick.com/userfiles/file/badal.pdfIn PDF document text
    • https://bursaceviritercume.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614139f2820db---87884591467.pdfIn PDF document text
    • http://www.ufolep-69.com/contenus/files/3350987642.pdfIn PDF document text
    • http://chizclean.ru/files/fck/file/bobobedewaripaxugewenoko.pdfIn PDF document text
    • http://proxima-design.cz/files/file/jozetox.pdfIn PDF document text
    • http://www.laterveer-biesenbeek.nl/ckfinder/userfiles/files/nibuxupoliwagasukujopid.pdfIn PDF document text
    • http://partnercable.com/files/49549503639.pdfIn PDF document text
    • http://kimbuunguyen.com/uploads/userfiles/file/77805306754.pdfIn PDF document text
    • http://futuralagoparking.eu/userfiles/files/xezovanaguvekuro.pdfIn PDF document text
    • http://sportingfoundation.com/uploads/file/91381617959.pdfIn PDF document text
    • http://jts-electrical.co.uk/ckfinder/userfiles/files/80376584380.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/PmAiG5ZyT-k/uplcv?utm_term=dolby+surround+for+androidPDF 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_off0000b43a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB43A 10472 bytes
SHA-256: 7305631f7b66c46f8558e08fe4ed99184e846d6a8d341bbafb1bc46f1455b8b2
font_01_sfnt_off0000cc0a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCC0A 16312 bytes
SHA-256: 095cf85082c979708a073b47d91bfa17f5d3d00e9864840d3bb7c54095ebdd32
font_02_sfnt_off0000f549.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF549 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1