Malicious PDF — malware analysis report

Static analysis result for SHA-256 ef58bd33c10819ff…

MALICIOUS

PDF

88.4 KB Created: 2021-07-24 20:13:25 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-31
MD5: bebc8f189e4dee02de33c5a1135a87f5 SHA-1: 339aeedce4b9f513de8b66a73622c22a2ebb67f2 SHA-256: ef58bd33c10819ffd3a47ccffa03ab333cc1e8a794674223aa3cab0a2415463f
96 Risk Score

Malware Insights

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

The PDF contains a large number of embedded URLs, many of which point to compromised WordPress sites. The ML classifier strongly indicates maliciousness, and the heuristic firings suggest this PDF is part of a link farm designed to manipulate search engine results or distribute further malware. No scripts were extracted, limiting the analysis of direct execution capabilities.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9993

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://sarahscupcakery.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bec07f107c5---xizir.pdf In PDF document text
    • https://www.teppiche-waschen-hamburg.de/wp-content/plugins/formcraft/file-upload/server/content/files/1607d403797b7a---tixojonodowidarid.pdfIn PDF document text
    • http://goldenagegroup.vip/userfiles/file/lunedofewidifobew.pdfIn PDF document text
    • https://bodymason.com/user_uploads/files/gezukizovevekapuxenodazor.pdfIn PDF document text
    • http://cn-junsheng.com/upload/file///202171204714220.pdfIn PDF document text
    • http://penoplex24.ru/wp-content/plugins/formcraft/file-upload/server/content/files/1607283b293814---dotagitegub.pdfIn PDF document text
    • https://elicopter-de-inchiriat.ro/wp-content/plugins/formcraft/file-upload/server/content/files/160752bcaa2f77---bekonesazelepuditukoto.pdfIn PDF document text
    • http://lutechmed.com/Images_upload/files/sibuwubadobuzanobedume.pdfIn PDF document text
    • https://pabausa.org/wp-content/plugins/formcraft/file-upload/server/content/files/1609dbb4c1b94c---98698898265.pdfIn PDF document text
    • http://vilaportugal.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ac325d1d2a7---senuvezoja.pdfIn PDF document text
    • http://ranaghatpchsschool.org/userfiles/file/23375825305.pdfIn PDF document text
    • https://www.aironface.com/wp-content/plugins/super-forms/uploads/php/files/41abc38bbb4406d4ffacc63352046cbd/8860724988.pdfIn PDF document text
    • https://rffsev.ru/wp-content/plugins/super-forms/uploads/php/files/ec999ca3f2a56bed69f9dabbf2919602/wojilewimepukorikawam.pdfIn PDF document text
    • http://southport1969.com/clients/861680/File/11288303408.pdfIn PDF document text
    • http://xedaptheduc.net/app/webroot/uploads/files/65493628664.pdfIn PDF document text
    • https://kolodezrus.ru/wp-content/plugins/super-forms/uploads/php/files/fbcdf186210dc6f55222747992ce7ca4/zaxiwufagibimojikiw.pdfIn PDF document text
    • http://flexa.cz/docs/file/11292785947.pdfIn PDF document text
    • http://berbun.com/user_img/file/20365609280.pdfIn PDF document text
    • http://holyfamilycyo.org/clients/37654/File/zeduko.pdfIn PDF document text
    • https://www.rath-catering.de/wp-content/plugins/formcraft/file-upload/server/content/files/16087abe849999---36855573448.pdfIn PDF document text
    • https://alfa-clining.ru/wp-content/plugins/super-forms/uploads/php/files/f445988611bdbb53478776902f1f6c6b/97358444931.pdfIn PDF document text
    • http://maxitelt.no/wp-content/plugins/formcraft/file-upload/server/content/files/1606cf80570abc---17664347742.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/YTWXjIUwRh0/uplcv?utm_term=atomic+habits+audiobook+free+download+mp3PDF 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_off0000f419.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF419 11456 bytes
SHA-256: c50f78784a9f1a0b6085411eb505e3d56745ba56722f4dc0a9b750d64795d89c
font_01_sfnt_off00010ede.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10EDE 16772 bytes
SHA-256: 1ab306dbf781d939d094de9445384f884e838a5d3db847c853310474236a2e6c
font_02_sfnt_off00013ab3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13AB3 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1