Malicious PDF — malware analysis report

Static analysis result for SHA-256 cd1f4bc4a9154a22…

MALICIOUS

PDF

70.8 KB Created: 2021-09-19 05:05:52 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: ebd73570376551900f79e60d83878de0 SHA-1: 11af024e6ccde5f52ea5cec01a6345644b1fc4fc SHA-256: cd1f4bc4a9154a22ef7be36ea37be894f2ea84603534e0245fe7c3e625a6e695
96 Risk Score

Malware Insights

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

The PDF contains numerous links to external PDF files, many hosted on domains associated with compromised CMS uploads or disposable hosting, indicating a link farm designed to redirect users. The ML classifier strongly flagged this PDF as malicious. While no scripts were extracted, the structure and URL patterns suggest a phishing or malware distribution attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

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://3e-recycling.ru/app/webroot/filesfiles/62098773823.pdf In PDF document text
    • http://magyaringatlanadatbazis.hu/dev/_user/file/23502036424.pdfIn PDF document text
    • https://ptogel2.com/contents/files/11636873318.pdfIn PDF document text
    • https://mysilo.com/upload/ckfinder/files/benamokotatixebedisimetir.pdfIn PDF document text
    • http://espaciocultivarte.com/ckfinder/userfiles/files/katibobamixosuwitididafut.pdfIn PDF document text
    • http://www.kidnuri.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613cec84186a4---43899237089.pdfIn PDF document text
    • http://novafish.it/userfiles/files/zivokoton.pdfIn PDF document text
    • https://jamisonfurnace.ca/userfiles/files/29237809178.pdfIn PDF document text
    • http://big-blue-bus.com/pics/fotos/1/file/88513440790.pdfIn PDF document text
    • https://www.americanapi.com/wp-content/plugins/formcraft/file-upload/server/content/files/16131c0b2783ee---55756142637.pdfIn PDF document text
    • http://mnogonomerov.ru/uploads/file/tewigu.pdfIn PDF document text
    • https://telechips.com/ckfinder/userfiles/files/bifezeseleriz.pdfIn PDF document text
    • https://helices-evra.com/userfiles/file/tosonumaforawigojaxo.pdfIn PDF document text
    • http://zeroseistudio.eu/userfiles/files/45084868379.pdfIn PDF document text
    • http://eshop-kocicinadeje.cz/files/file/dizurazebusetaziko.pdfIn PDF document text
    • https://accesoriosalmayor.com/images/userfiles/file/87428415608.pdfIn PDF document text
    • http://namhungholdings.com/uploads/ckfinder/files/16232036391.pdfIn PDF document text
    • https://fenixfalt.com/userfiles/file/xuviforogegabowutarajab.pdfIn PDF document text
    • https://regalcabs.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/16132c28a4aaf4---zupagimeredikelu.pdfIn PDF document text
    • http://baoveantam.info/upload/files/wusazemolozawedadolejetu.pdfIn PDF document text
    • https://kamarkosong.com/contents/files/32952780938.pdfIn PDF document text
    • https://garnizone.com/userfiles/file/wedobetiz.pdfIn PDF document text
    • http://ibconsulting.it/userfiles/files/28497740254.pdfIn PDF document text
    • http://abwcoliseum.com/uploads/files/78437394909.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/3vuEKuznOb8/uplcv?utm_term=watch+coming+2+america+123PDF 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_off0000b415.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB415 15952 bytes
SHA-256: 5bcf13359b7043ae25d93be3ed251d7c0821bb5a88ee8184e77a6c958c6981d2
font_01_sfnt_off0000dd0a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDD0A 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000f521.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF521 10800 bytes
SHA-256: fdcdc6c5c4262d4a1ecef867150dde7d07c28b0f7d27a7cbfcf7e7b431c99491