Malicious PDF — malware analysis report

Static analysis result for SHA-256 4d36489f5071e25d…

MALICIOUS

PDF

95.6 KB Created: 2021-06-29 15:33:12 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-14
MD5: 1acb89f97d06f9d30ce0bec11b64917b SHA-1: 98a8f92829c31f02a30dfe4efb195c5534c71622 SHA-256: 4d36489f5071e25d65f5543f370f31c33acc08e4a332ae962c0b9204cb015b96
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 external URIs and link farm patterns, indicating a likely attempt to manipulate search engine rankings or redirect users to malicious sites. The ML classifier strongly flagged this PDF as malicious, supporting the assessment of a malicious link farm. No scripts were extracted, and the document body was unreadable, so the specific payload or ultimate goal remains unknown.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9966

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://ketchas.ru/uplcv?utm_term=shadowing+let%27s+speak+japanese+intermediate+to+advanced+edition+pdf PDF link annotation
    • http://www.yourhealthyourchoice.org/wp-content/plugins/formcraft/file-upload/server/content/files/160a773c51ed62---67345595913.pdfIn PDF document text
    • http://stepsforstarlight.org/clients/c/c6/c668404594a1c08d975ab50c7bec58f6/File/tovamobegapejulanafijene.pdfIn PDF document text
    • https://joyfool.art/wp-content/plugins/super-forms/uploads/php/files/91420c3da6237e17d1c211ed4ba46c43/warufuvufepaguxojipe.pdfIn PDF document text
    • https://sandalyecenneti.com/wp-content/plugins/super-forms/uploads/php/files/ut6fr2mk0nf78qfcjksi1n8941/14527112897.pdfIn PDF document text
    • https://www.advids.co/wp-content/plugins/formcraft/file-upload/server/content/files/1609477df63740---fuzapujogedobal.pdfIn PDF document text
    • http://sochistandart.com/ckfinder/userfiles/files/34268466514.pdfIn PDF document text
    • https://garyjetcenter.com/wp-content/plugins/super-forms/uploads/php/files/347ed12a8b09ba8f3f08735a210c8060/28764102025.pdfIn PDF document text
    • http://ccforum.kr/uploads/file/1624508323.pdfIn PDF document text
    • http://dientrotiendathc.com/media/ftp/file/dugunaroriwuk.pdfIn PDF document text
    • https://gk-termopanel.ru/wp-content/plugins/super-forms/uploads/php/files/20c4a760b5265299d6d3b49419a51c4f/zarabid.pdfIn PDF document text
    • http://www.icodar.com/wp-content/plugins/formcraft/file-upload/server/content/files/16078d6a4148d6---runoreja.pdfIn PDF document text
    • http://www.telsercom.com/wp-content/plugins/formcraft/file-upload/server/content/files/160913ac50838a---38324698292.pdfIn PDF document text
    • http://446888.top/userfiles/file/xabazox.pdfIn PDF document text
    • http://rhondachem.com/d/files/vonutubonininusejosez.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 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000f1e8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF1E8 17996 bytes
SHA-256: 360795bdc70466a2376e2f023b829bbfdfb8e1f94a7a0ecb5da5ad45bcd2ceac
font_01_sfnt_off000121b2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x121B2 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000139c9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x139C9 11552 bytes
SHA-256: 11769b1d58e977b3f1a69a4f3c81f3e1b64229983f57c7835c450adc27095fac
font_03_sfnt_off000154d9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x154D9 8184 bytes
SHA-256: 3145bc4c48a5cc4fdf7ffeafb419dba1fb8110b61b5d4155e89ddf118b3ca54a