Malicious PDF — malware analysis report

Static analysis result for SHA-256 b815af4dbacbb590…

MALICIOUS

PDF

92.8 KB Created: 2021-07-24 01:26:20 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 4a094aa156b0a996fa2452405ab8639b SHA-1: 4fd21f417c58b960092fb726dd561442926f77f6 SHA-256: b815af4dbacbb5900b39e892e2d7fc7d3be0f914cff84ec1012324c8b856454c
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file contains a large number of embedded URLs, many of which point to compromised CMS upload directories or disposable hosting, indicating a link farm designed for malicious redirection. The ML classifier and ClamAV detection strongly suggest malicious intent, likely related to phishing or malware delivery. Although no scripts were explicitly extracted, the nature of the URLs and the heuristic firings point towards a phishing or malware distribution campaign.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9932

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 http://papinchess.ru/userfiles/file/2623211987.pdf In PDF document text
    • http://www.rolstoellift.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a1d01692ccc---90885294735.pdfIn PDF document text
    • https://minlinart.com/archive/upload/files/90845281091.pdfIn PDF document text
    • https://szabobuszberles.hu/files/files/gevogizurerufagigopi.pdfIn PDF document text
    • http://myucmas.com/userfiles/file/25712683111.pdfIn PDF document text
    • http://www.iycadana.org/wp-content/plugins/super-forms/uploads/php/files/n5b3ranc9sh9lur3suql79u572/napimabugizosekaz.pdfIn PDF document text
    • http://thanhlamresort.vn/wp-content/plugins/formcraft/file-upload/server/content/files/160a3087e4e77c---rodurubumirugokudav.pdfIn PDF document text
    • http://macabrey-luthier.fr/data/Files/29846345899.pdfIn PDF document text
    • http://lawcab.ru/wp-content/plugins/formcraft/file-upload/server/content/files/160747cb530a51---37133276681.pdfIn PDF document text
    • https://agribusiness.pk/wp-content/plugins/formcraft/file-upload/server/content/files/160ab241c1e679---60338870481.pdfIn PDF document text
    • http://www.sparkprototypes.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a635a34e23e---wadojifukaxila.pdfIn PDF document text
    • http://studiogallerani.it/userfiles/files/bifoxalome.pdfIn PDF document text
    • https://www.grecosalesinternational.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606f6bbeae396---65647098052.pdfIn PDF document text
    • https://dentalrud.com/userfiles/file/fujefanafidafulowore.pdfIn PDF document text
    • https://vpntraffic.com/upload/files/25952025317.pdfIn PDF document text
    • http://vegasoft.hr/wp-content/plugins/formcraft/file-upload/server/content/files/160b4f3fa6b7f6---jirubibibizifezerurape.pdfIn PDF document text
    • https://ahha.az/userfiles/file/17933496758.pdfIn PDF document text
    • https://samsungvrvklima.com/upload/ckfinder/files/29649575786.pdfIn PDF document text
    • http://neuragen.ca/wp-content/plugins/formcraft/file-upload/server/content/files/1609d1523702cd---xanetolizoxag.pdfIn PDF document text
    • https://alice-immo.com/userfiles/file/7911224733.pdfIn PDF document text
    • http://sobsai.com/ckfinder/userfiles/files/15680806792.pdfIn PDF document text
    • https://www.fmworks.com.tr/wp-content/plugins/super-forms/uploads/php/files/ukiq3141snepu91ou9ir1r5ntb/sapux.pdfIn PDF document text
    • https://www.hinkler.com.au/application/third_party/ckfinder/userfiles/files/85319071052.pdfIn PDF document text
    • https://skyfireconsulting.com/wp-content/plugins/super-forms/uploads/php/files/jlurj52ef13rob1so1g739lt7m/88605493794.pdfIn PDF document text
    • http://saothienemb.com/uploads/images/files/81156621411.pdfIn PDF document text
    • http://abwlargo.com/uploads/files/77083238964.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/zMnd8XtcwSM/uplcv?utm_term=what+is+colorimetric+principlePDF 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_off00010593.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10593 17688 bytes
SHA-256: f9f3da51029a58471408ee8a93a9ff13138a936e3178a6d75d9481e378c02226
font_01_sfnt_off00013436.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13436 10632 bytes
SHA-256: a3a663fb5774716511a040527f23080eb1e4ec67be88ff36147f009776c2cfde
font_02_sfnt_off00014c63.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x14C63 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1