Malicious PDF — malware analysis report

Static analysis result for SHA-256 f6420555f67903ed…

MALICIOUS

PDF

79.5 KB Created: 2021-08-29 08:18:02 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-17
MD5: 1fcbc874dc3760ecdc248ee27a340904 SHA-1: 8e7468f7cfed078294d23e807ca873a795797972 SHA-256: f6420555f67903ed29849e6579a27711ebd451427ec8f4f8c2f92c1cbaf36d58
96 Risk Score

Malware Insights

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

The PDF contains a link farm pointing to numerous distinct hosts, many of which appear to be compromised WordPress sites. The ML classifier strongly indicated maliciousness, and the presence of multiple external URIs suggests an attempt to redirect users to potentially harmful content or for SEO manipulation. No scripts were extracted, but the structure and heuristic firings point to a malicious link farm.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9978

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://law.com.sg/wp-content/plugins/super-forms/uploads/php/files/3d7bf6c105598bc6c38fb9062138a452/11161496858.pdf In PDF document text
    • https://philly.drinkpoint.com/uploads/files/kalikabunudusa.pdfIn PDF document text
    • https://www.phoenixdentalacademy.co.uk/wp-content/plugins/super-forms/uploads/php/files/4ce1ac284968b2fad767d3ffddab8101/6629754102.pdfIn PDF document text
    • http://brickchamber.com/ckfinder/userfiles/files/rodubagefilizedotap.pdfIn PDF document text
    • https://ohligschlaeger-berger.de/wp-content/plugins/formcraft/file-upload/server/content/files/1608ab86c47967---97994732194.pdfIn PDF document text
    • http://milcontabil.com.br/wp-content/plugins/super-forms/uploads/php/files/mkuaq2i152s12tb8nnbf3f07p0/rifuwulefetewad.pdfIn PDF document text
    • http://rethabise.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/1606ced788cea2---semuxamus.pdfIn PDF document text
    • https://carstenrath.com/wp-content/plugins/super-forms/uploads/php/files/qvpa0bcb90nf9bhqp4iflumgme/bewasi.pdfIn PDF document text
    • http://lirealestatelitigator.com/wp-content/plugins/super-forms/uploads/php/files/6d880a6d27c1524912143677d91ffbf3/19449831178.pdfIn PDF document text
    • https://totalyoumovement.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606f2ae32f7db---42895301618.pdfIn PDF document text
    • https://jaunimodienos.lt/wp-content/plugins/super-forms/uploads/php/files/hsj0nq2p7gcu0qb3beec49bod2/katokilazowi.pdfIn PDF document text
    • http://freehajjandumrah.com/admin/admin/uploadfiles/file/tefefutujo.pdfIn PDF document text
    • http://camberwelltaxi.com/survey/userfiles/files/wajukulopomewudepefe.pdfIn PDF document text
    • https://prawobrzeze.info/userfiles/file/kowirafimogafonato.pdfIn PDF document text
    • http://vaynhe.com/upload/files/gavojivanubuzedewelalur.pdfIn PDF document text
    • https://aspit.ro/imagini_ws/jegudinor.pdfIn PDF document text
    • https://tranhtreo.com/images/ckeditor/files/14174739527.pdfIn PDF document text
    • https://beachesbrewing.com/wp-content/plugins/super-forms/uploads/php/files/70e2e1dadab39d5dac1befd25f63db8e/22120572854.pdfIn PDF document text
    • http://ipvoicenj.com/wp-content/plugins/formcraft/file-upload/server/content/files/160cb434fd0a65---64757064620.pdfIn PDF document text
    • https://g-ortho.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160c85276b9c1b---48238675383.pdfIn PDF document text
    • http://evabody.ro/wp-content/plugins/formcraft/file-upload/server/content/files/1608bba99867ab---31612865834.pdfIn PDF document text
    • https://neoville.ru/wp-content/plugins/super-forms/uploads/php/files/661b5b4653398f95e3231d66a4812db7/felukemofefefoja.pdfIn PDF document text
    • http://artmetinc.com/wp-content/plugins/formcraft/file-upload/server/content/files/161044d8868abe---dorunosepivasiwilox.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/3vuEKuznOb8/uplcv?utm_term=maine+driver%27s+license+renewal+real+idPDF 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_off0000d72f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD72F 16004 bytes
SHA-256: a072aef537ab631a8d5c654589ed555ae4be5988271a5cf0bc927332262929b0
font_01_sfnt_off0001009f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1009F 10324 bytes
SHA-256: 9a76eae499d058d71bfa21dbbc4972247b4986201860e48483470d3e07f5d908
font_02_sfnt_off0001180b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1180B 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1