Malicious PDF — malware analysis report

Static analysis result for SHA-256 4a8238f8701d16fc…

MALICIOUS

PDF

96.7 KB Created: 2021-09-05 12:12:24 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: d09c2f31c69b30abeb1bf556577751cb SHA-1: 836d7a6aa97e65444594bd2f87279383e25e43bd SHA-256: 4a8238f8701d16fce057ff1464d5db803f051fc82a8dddfdd8bc33b5ffb39309
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 multiple compromised WordPress sites, indicating a phishing or malware distribution attempt. The ML classifier strongly flagged this PDF as malicious, and the presence of numerous external URIs supports this assessment. No scripts were extracted, but the document structure itself is designed to redirect users to potentially harmful content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9965

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://centrosteadycam.it/wp-content/plugins/super-forms/uploads/php/files/4e14700592b278115d106389903695b7/lonodogixipasaris.pdf In PDF document text
    • https://completecollegestrategies.com/wp-content/plugins/super-forms/uploads/php/files/c620e0ffdc6f8e116261309005c04a6b/ripowepinujekadoximoku.pdfIn PDF document text
    • http://www.ausafrica.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/16075f696e0cb5---5808167732.pdfIn PDF document text
    • http://99hospitalitygroup.com/ckfinder/userfiles/files/36853302542.pdfIn PDF document text
    • https://o-dance.com/upload/files/34658027328.pdfIn PDF document text
    • https://klingende-zeder.de/wp-content/plugins/formcraft/file-upload/server/content/files/16090af6d7050d---pivosekuzonomesit.pdfIn PDF document text
    • http://davcpundri.com/css/file/ganajuxixizipofiwise.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a7758dacd9d---rapufuboxegef.pdfIn PDF document text
    • http://inistor.com/ufiles/files/18693166328.pdfIn PDF document text
    • https://digireg.li/upload/nolapas.pdfIn PDF document text
    • http://snp-ent.com/files/fckeditor/file/52003358061081121ae13a.pdfIn PDF document text
    • http://www.olympussverige.se/wp-content/plugins/super-forms/uploads/php/files/2lbop2asmnq0cpf2vsbs3hruj7/xabemadasosutoranave.pdfIn PDF document text
    • http://geoscan.it/userfiles/files/86625991154.pdfIn PDF document text
    • https://www.bouwenaaneensterkwerkgeversmerk.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160a11c229c7e3---gimuvimilisofawosuzali.pdfIn PDF document text
    • https://webhosting4.net/media/file/womanevovozelakevivit.pdfIn PDF document text
    • http://www.shipsupply.co.mz/wp-content/plugins/formcraft/file-upload/server/content/files/160b3b3681de6a---43940880548.pdfIn PDF document text
    • http://esoftland.com/userfiles/file/dofiwuxifurot.pdfIn PDF document text
    • https://conexusinternational.com/ckfinder/userfiles/file/17047960160.pdfIn PDF document text
    • http://rmgoals.com/userfiles/files/zakasogaxa.pdfIn PDF document text
    • http://moveisgarciadigital.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1609ab92b6190d---80772180216.pdfIn PDF document text
    • https://www.rydalmereprestige.com.au/wp-content/plugins/super-forms/uploads/php/files/tvg7hp3ua9fj445b8fd0scovm8/pebuxidotezewirena.pdfIn PDF document text
    • http://drumlockingclamp.com/FCK_Editor_Images/files/25325229220.pdfIn PDF document text
    • http://dmhu.eu/uploads/uplib/file/nuxowabakujufevubute.pdfIn PDF document text
    • https://kamarkosong.com/contents//files/jerazasidoxokeredu.pdfIn PDF document text
    • http://ecbpolska.pl/wp-content/plugins/super-forms/uploads/php/files/05504bdc3c17acdc92b6d8ff857228f8/52581661956.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/6naE_Nh8_CY/uplcv?utm_term=past+simple+worksheet+elementary+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://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_off0001172d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1172D 16988 bytes
SHA-256: 9612c6625483d7a280d1b87e130f180cfd246b7ab7ddd1ea7b41d00c8c83dba1
font_01_sfnt_off0001433b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1433B 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00015b52.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x15B52 11056 bytes
SHA-256: 8f46ea76dad72b470a05e6a0d5ab8c3a3f483b9a7c067bb8eaa98e78afda3ac8