Malicious PDF — malware analysis report

Static analysis result for SHA-256 7b4534406680e638…

MALICIOUS

PDF

85.0 KB Created: 2021-08-15 22:16:56 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 3a60f58e0489286ac1d2b4147326f62e SHA-1: 1cfcae3e6e2fdebc3f99daf07adfd26a6760892c SHA-256: 7b4534406680e63802acc59f3605c23ce116702ac3f837c90c57e334a898c592
96 Risk Score

Malware Insights

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

The PDF file contains a large number of embedded URLs, many of which point to compromised WordPress sites and disposable hosting domains. This behavior is characteristic of a link farm designed to manipulate search engine rankings or distribute malicious payloads. The ML classifier strongly indicated maliciousness, supporting the assessment of a malicious link farm.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9984

Heuristics 5

  • 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://wastran.ru/uplcv?utm_term=what+are+the+different+types+of+hdmi+connectors PDF link annotation
    • https://relleno-acidohialuronico.com/wp-content/plugins/super-forms/uploads/php/files/21a1dd1034c3400feda741e432c6bd58/wotame.pdfIn PDF document text
    • http://centromp.it/userfiles/files/perosusad.pdfIn PDF document text
    • http://thangmayedex.com/webroot/img/files/13513515433.pdfIn PDF document text
    • http://www.thelawchamber.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608fcc9b0ab4f---zasawuwirafeti.pdfIn PDF document text
    • http://volamtuyetthe.com/userfiles/file/pefezuf.pdfIn PDF document text
    • https://ketgate.eu/wp-content/plugins/super-forms/uploads/php/files/0c424baff2b4c7872fc07c0f5acdd760/65286405125.pdfIn PDF document text
    • http://www.holzbau-hoelzl.at/wp-content/plugins/formcraft/file-upload/server/content/files/160ad64f326ea7---zelolutugopugesoku.pdfIn PDF document text
    • http://sola-brothers.com/userfiles/file/petijemuridixa.pdfIn PDF document text
    • http://westleyden72reunion.com/clients/4/46/469dc9162705cbff2d1fbe132f144f37/File/30442536301.pdfIn PDF document text
    • https://www.hed-endo.hr/wp-content/plugins/formcraft/file-upload/server/content/files/16079462f66642---fobubalekurolaf.pdfIn PDF document text
    • http://pyroglobal.sk/app/webroot/files/userfiles/files/ruxigagoxutinazisakusiru.pdfIn PDF document text
    • https://unicornproduction.gr/wp-content/plugins/super-forms/uploads/php/files/009459a36fa67c6eba9637ded600e701/64711166866.pdfIn PDF document text
    • http://www.segurosfacility.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1609dccb87daf9---jagox.pdfIn PDF document text
    • http://lagostena.it/userfiles/files/jafosobamazonezo.pdfIn PDF document text
    • https://qualitymattressfactory.com/admin/userfiles/file/ponomaropiwunofanagegu.pdfIn PDF document text
    • http://firanywiktoria.pl/uploads/editor/file/85088881136.pdfIn PDF document text
    • http://thaisomboonautopart.com/userfiles/files/pozabizidebenabopujuna.pdfIn PDF document text
    • http://progfin.pl/userfiles/file/60440513106.pdfIn PDF document text
    • https://sanaspinler.com/calisma2/files/uploads/povudupirozexosew.pdfIn PDF document text
    • https://www.northernillumination.com/wp-content/plugins/super-forms/uploads/php/files/5b28fa37f63e3be6c8c3b56387b955ca/35838157769.pdfIn PDF document text
    • http://perlawarmii.pl/userfiles/file/gelaberobowegebutunafu.pdfIn PDF document text
    • http://akbmodel.com/wp-content/plugins/formcraft/file-upload/server/content/files/16102fe9ab35e5---poxadaseluwuwinazonigojil.pdfIn PDF document text
    • https://dunakanyarfesto.hu/ckfinder/userfiles/files/33520410657.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_off0000e674.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE674 10948 bytes
SHA-256: e619fb68f089091c025da42ba0c5b5b8ed2f64dfe14a9e8890afbfcdb8d57fb7
font_01_sfnt_off0000ffb3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFFB3 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000117c5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x117C5 16732 bytes
SHA-256: 8906593b6efcd51429d6f00fefa0316d4f584de7b7a34b96b24350c3fec21361