Malicious PDF — malware analysis report

Static analysis result for SHA-256 6f5d422bf98caf44…

MALICIOUS

PDF

81.0 KB Created: 2021-09-12 08:25:08 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 3d59edadaf1872a804ba06c704dfce78 SHA-1: 320504fe9475d953249350ab1d99c6ee553d4024 SHA-256: 6f5d422bf98caf44977d5d18f7551bdd37d0a5f0b96c42f95f4cec1528b1206d
116 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URIs pointing to various websites, many of which appear to be compromised CMS uploads. The ML classifier strongly indicates maliciousness, and the presence of multiple links to potentially malicious content suggests a link farm attack pattern. While no scripts were explicitly extracted, the PDF structure and URI findings are sufficient to infer malicious intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9949

Heuristics 6

  • Clickable URI points to raw IP address medium PDF_URI_IP_LITERAL
    PDF contains a clickable HTTP(S) action whose host is a literal IPv4 address. Legitimate documents normally link to named domains; raw-IP destinations are common in disposable phishing and malware-delivery infrastructure.
  • 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://harpethvalleyhealth.com/wp-content/plugins/super-forms/uploads/php/files/58f240138cc194a659b8714e326e4953/xilubizomorod.pdf In PDF document text
    • http://montpellier-businessplan.fr/mbp/upload/images/images/upload/ckfinder/18948232589.pdfIn PDF document text
    • http://isleford.com/filespath/files/20210912115425.pdfIn PDF document text
    • https://alfa-clining.ru/wp-content/plugins/super-forms/uploads/php/files/2c9ea14116e208def6364eca4f5d3ca1/76268187462.pdfIn PDF document text
    • https://www.a2zmedical.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/16134fb26c9eca---62991014648.pdfIn PDF document text
    • http://physio-praxismitte.de/userfiles/zojuwe.pdfIn PDF document text
    • https://childprotectionindia.com/lexcyberia/userfiles/files/rufowesivoro.pdfIn PDF document text
    • https://verlauf-ekb.ru/admin/ckfinder/userfiles/files/33910353965.pdfIn PDF document text
    • http://amuseonline.com/absite/userfiles/file/25004743444.pdfIn PDF document text
    • https://alharithiforcameras.com/ckfinder/userfiles/files/kujetemufa.pdfIn PDF document text
    • http://viettelhaiphong.me/data/dulieu/files/90181744822.pdfIn PDF document text
    • http://sangtaoad.com/uploads/userfiles/file/zurokepovexivinexo.pdfIn PDF document text
    • https://sjamsul-hidajat.id/ck_uploads/uploads/files/54172927671.pdfIn PDF document text
    • http://wideanglepackaging.com/ckfinder/userfiles/files/polewenimititudoruwune.pdfIn PDF document text
    • http://wuyioutdoor.com/userfiles/file/munufazapinetakojoxenel.pdfIn PDF document text
    • http://koreabulk.net/userData/board/file/fenesozeseg.pdfIn PDF document text
    • https://albertoangel.sinecsas.com/ckfinder/userfiles/files/50431428805.pdfIn PDF document text
    • http://torremaggiore.sitmap.it/files/files/32814008674.pdfIn PDF document text
    • http://a1-automotivegroup.com/upload/files/6470100163.pdfIn PDF document text
    • http://140.121.125.49/ckfinder/userfiles/files/20210909_201137.pdfPDF link annotation
    • https://comodee.com/wp-content/plugins/formcraft/file-upload/server/content/files/16137f34b030da---31910995961.pdfIn PDF document text
    • http://sarica.com.tr/ckfinder/userfiles/files/76981097688.pdfIn PDF document text
    • http://studiotecnicoprato.eu/userfiles/files/molukazedekotimuzuluzamu.pdfIn PDF document text
    • http://rulife.ru/ckfinder/userfiles/files/53963096399.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/GLLx1DTH0VQ/uplcv?utm_term=bicep+workouts+gymPDF link annotation
    • https://tes-sys.com/uploads/ckfinder/files/20210909/16311341149491.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_off0000d87c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD87C 17420 bytes
SHA-256: 67010d8571038e44dac3ccc34ef8fbd8db9f67ea44de1904d1dd2eaf64c390f2
font_01_sfnt_off0001056f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1056F 10848 bytes
SHA-256: ddb8efaf3c19b0744e7485566062dca33b50a5ccb823f6dcf08516dd7b3775ed
font_02_sfnt_off00011eb3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11EB3 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1