Malicious PDF — malware analysis report

Static analysis result for SHA-256 de1f2a056818e1c5…

MALICIOUS

PDF

84.2 KB Created: 2021-09-01 12:24:32 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: a6551562665468596bfe16f2be9cab12 SHA-1: 84194e758778823bfa84a43b2f7b04fe3dcb7f26 SHA-256: de1f2a056818e1c545625e41010c10254455315ed5d598003bd898cbf94e92a0
96 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many of which point to compromised CMS uploads or disposable hosting, indicating a link farm. The ML classifier strongly flagged this PDF as malicious. While no scripts were extracted, the structure and URL patterns suggest an attempt to manipulate search engine results or redirect users to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9981

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://newgrids.com/userfiles/file/92484886790.pdf In PDF document text
    • http://anhopphat.com/uploads/files/pudavusutekemumimukam.pdfIn PDF document text
    • http://emke.hu/uploads/ckfinder/userfiles/files/25196120167.pdfIn PDF document text
    • http://manufim.co.il/wp-content/plugins/formcraft/file-upload/server/content/files/160bd8f2969f62---57496922796.pdfIn PDF document text
    • http://pwr-tech.ru/userfiles/file/58238604188.pdfIn PDF document text
    • http://airconbank.com/upload/fckeditor/file/rixukatezujig.pdfIn PDF document text
    • http://webhenevents.com/clients/868374/File/dimijuzelotipo.pdfIn PDF document text
    • https://derey.nl/app/webroot/files/userfiles/files/gulusimazososovar.pdfIn PDF document text
    • https://sieuthigo.vn/upload/ck/files/kulinula.pdfIn PDF document text
    • https://faceless.me/userfiles/files/61656207183.pdfIn PDF document text
    • https://ccaquebec.com/userupload/files/levifelizax.pdfIn PDF document text
    • http://mirrorgallery.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606cca9ed3b2e---tosumezo.pdfIn PDF document text
    • http://dyglas.com/userData/board/file/73065906502.pdfIn PDF document text
    • https://agrachoff.ru/wp-content/plugins/super-forms/uploads/php/files/4265a07d8ec687f0444a39f309dc1085/wetagavubulusapo.pdfIn PDF document text
    • http://cgt-fo-csc.fr/wp-content/plugins/formcraft/file-upload/server/content/files/16088627fd697f---tagepekovukuvizivirul.pdfIn PDF document text
    • https://www.themeshcowork.com/wp-content/plugins/super-forms/uploads/php/files/a9ff6b755c1b88b47c6f5781eb2c2082/nagolanetemoponere.pdfIn PDF document text
    • https://lawpropertyconsultants.co.uk/wp-content/plugins/super-forms/uploads/php/files/q56kq79jb0a91186v4knmujk7d/79804397167.pdfIn PDF document text
    • http://www.thebetterinsurance.com/wp-content/plugins/formcraft/file-upload/server/content/files/160cd49ab6bf4f---tiwisiwe.pdfIn PDF document text
    • http://acudrved.com/ckfinder/userfiles/files/92465452556.pdfIn PDF document text
    • https://suhrsmad.dk/wp-content/plugins/formcraft/file-upload/server/content/files/1608f684041b02---75086505720.pdfIn PDF document text
    • https://amenagementsoleil.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ac3e230f961---30398916115.pdfIn PDF document text
    • https://sellos-mecanicos.com/wp-content/plugins/super-forms/uploads/php/files/8bbd617c0738d0f46f0fe2327b855974/jekepabukikanituvapev.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/Om9ozkHLxGw/uplcv?utm_term=lesson+5+skills+practice+graph+a+line+using+interceptsPDF 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_off0000e32c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE32C 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000fb3e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFB3E 17656 bytes
SHA-256: f4df8517ba036fbf454f5477584062499df10f62b95897e54c28941af8825ac7
font_02_sfnt_off00012920.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12920 10936 bytes
SHA-256: a68722dfaad131b73b6b4d86af77a35c5cd90ae0b7af10376529efc520dd5f48