Malicious PDF — malware analysis report

Static analysis result for SHA-256 d8be75f72abd5853…

MALICIOUS

PDF

75.4 KB Created: 2021-09-17 19:23:00 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 4e8ed3f058002c69a7e7550e0103723c SHA-1: 651440e74d6dafbdb971db4f16955d492ca62dd1 SHA-256: d8be75f72abd5853bdc491e2c278568ef84e1c23d07dc8969c110a3e987c8e4e
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 CMS upload directories or disposable hosting, suggesting a link farm designed to redirect users to potentially malicious sites. The ML classifier strongly indicates malicious intent, and the presence of compromised CMS links points towards a tactic of leveraging existing infrastructure for distribution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9980

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://pistant.ru/uplcv?utm_term=google+sign+in+apk+frp PDF link annotation
    • http://edu-soft.ru/site/htmlimages/file/22431521878.pdfIn PDF document text
    • https://www.karelo.com/uploads/File/55241419607.pdfIn PDF document text
    • https://bczenekar.hu/files/file/24741149505.pdfIn PDF document text
    • http://consulcongress.it/uploads/assets/file/19241885292.pdfIn PDF document text
    • https://a-guskov.ru/uploads/files/32449821152.pdfIn PDF document text
    • http://e-kva.ru/admin/ckfinder/userfiles/files/35837861915.pdfIn PDF document text
    • https://pasarantogel.com/contents/files/89082216645.pdfIn PDF document text
    • https://drjou-vc.com/upload/files/rasesemizevovufulubuj.pdfIn PDF document text
    • http://aceonlinementors.com/userfiles/file/75298762610.pdfIn PDF document text
    • https://autohausnschmidt.de/userfiles/file/gowebigoveled.pdfIn PDF document text
    • https://akemi.ro/hirek/file/71166547705.pdfIn PDF document text
    • https://www.18fire.com/wp-content/plugins/super-forms/uploads/php/files/167d890257a9c399425ca0cc0d95e95b/8344247178.pdfIn PDF document text
    • http://9262895.ru/ckfinder/userfiles/files/34621936702.pdfIn PDF document text
    • https://rireenfrance.com/images/upload/files/kalegilarowenigejuvi.pdfIn PDF document text
    • http://kevinmcallisterlaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/72247585366.pdfIn PDF document text
    • https://www.lumisolar.pe/wp-content/plugins/formcraft/file-upload/server/content/files/161413a6897f94---figaxobed.pdfIn PDF document text
    • http://jawarakreasi.com/file/pafej.pdfIn PDF document text
    • http://thcsnguyenvanhuyen.hoaiduc.edu.vn/ckfinder/userfiles/files/soxesesinugevag.pdfIn PDF document text
    • https://maribon.net/app/webroot/files/userfiles/files/rilubom.pdfIn PDF document text
    • http://ttlengenharia.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1613bfa5fdc700---marukodudofikaribuxupemi.pdfIn PDF document text
    • https://profession-your-dr.com/uploads/files/202109022304454217.pdfIn PDF document text
    • http://danangsculpture.com/uploads/image/files/32769382462.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 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000c5e2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC5E2 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000ddf9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDDF9 10564 bytes
SHA-256: 01da407f25b78468153b2694e31a77eed36cf33e6b6491592ce9ec5f1a527ffb
font_02_sfnt_off0000f631.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF631 16400 bytes
SHA-256: 8a8ff73a6d7fe3fbf0b40db6264c8fdcb703dac04f211a0beffd3ccf97eb0044