Malicious PDF — malware analysis report

Static analysis result for SHA-256 900e9a618d58041a…

MALICIOUS

PDF

65.7 KB Created: 2021-05-04 13:59:15 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-07-13
MD5: 220b4b69de683dcba28785e3fae23df1 SHA-1: 89a0eb0dd1dc64aa66327cea68964f0efdd82f8b SHA-256: 900e9a618d58041ad515c97c72b4ec32d7a26043502a64f7b1c8bb35ed99330b
96 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The PDF contains a link farm pointing to numerous compromised websites, likely intended to distribute further malicious content. The ML classifier strongly indicated maliciousness, and the presence of embedded URLs suggests an attempt to redirect users to malicious resources. No scripts were extracted, limiting the analysis of specific execution techniques.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9996

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 http://osullivanspressurewashing.com/wp-content/plugins/formcraft/file-upload/server/content/files/16079b051c10ad---jazeselazutu.pdf In PDF document text
    • https://www.democratum.com/wp-content/plugins/super-forms/uploads/php/files/3213d194b3ddb8c471d705e9e2219688/11478803987.pdfIn PDF document text
    • https://grahampropertytax.com/wp-content/plugins/super-forms/uploads/php/files/9a5081447f6469b2b04a2667763fd4a6/8259752804.pdfIn PDF document text
    • https://www.denisonlandscaping.com/wp-content/plugins/formcraft/file-upload/server/content/files/16071bf6736040---99971792675.pdfIn PDF document text
    • https://spencershaulageltd.co.uk/wp-content/plugins/super-forms/uploads/php/files/df121894cf76f3011210191c51ed8d91/5429507992.pdfIn PDF document text
    • https://hartwellcook.com/wp-content/plugins/super-forms/uploads/php/files/b5bf4227f82b145232f0588294f7ddb4/53420412916.pdfIn PDF document text
    • https://sg-design.top/wp-content/plugins/super-forms/uploads/php/files/e37f9035b92ed444ac4ff0ec13769587/56102405326.pdfIn PDF document text
    • https://www.mixedclass.com.au/wp-content/plugins/super-forms/uploads/php/files/sbdb7hsacu2gocsmnfgtv4qa0k/kufepifafuwuxotididi.pdfIn PDF document text
    • http://abapaposentados.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1607fb8b6168b7---melasusakusakovolafele.pdfIn PDF document text
    • http://www.kindytennis.com/wp-content/plugins/formcraft/file-upload/server/content/files/16078fdfb0f171---30879180892.pdfIn PDF document text
    • https://www.sehersirin.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607916a237e2e---63752007731.pdfIn PDF document text
    • https://www.spreefahrten-berlin.de/wp-content/plugins/super-forms/uploads/php/files/65m8bh8fc1rg8287icm3o66eal/putol.pdfIn PDF document text
    • http://phenix-security.fr/wp-content/plugins/formcraft/file-upload/server/content/files/160890b5242faa---mipidilowaroze.pdfIn PDF document text
    • https://daleel.global/wp-content/plugins/super-forms/uploads/php/files/8rdkq62v9d731p711vrrsgcgan/48180027500.pdfIn PDF document text
    • http://penoplex24.ru/wp-content/plugins/formcraft/file-upload/server/content/files/1606c726392913---nawizowitekanuvomasa.pdfIn PDF document text
    • https://lorenzonimmigrationlaw.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606f9d4e78428---wufasexuwabokegobov.pdfIn PDF document text
    • http://erfolgsapp.de/wp-content/plugins/formcraft/file-upload/server/content/files/160868bf41ffe2---vaxufenakomusanedofino.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/DOqCt-cVA4I/uplcv?utm_term=present+past+future+simple+tenses+exercises+pdfPDF 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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000cb95.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCB95 5372 bytes
SHA-256: 91a53c0d6b7c4b36e2b2501ce92173ade4e37f3cb353c990018c8f58a53511ab
font_01_sfnt_off0000ddc5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDDC5 9724 bytes
SHA-256: 0ba58b82332e3ac671a569c66baafc40c8515a1b8031f3b191e6cdef0200c710