Malicious PDF — malware analysis report

Static analysis result for SHA-256 8b9c843aaab3c360…

MALICIOUS

PDF

73.1 KB Created: 2021-09-11 19:34:32 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: 1c8c1790aab1f8ce1b1583f9b6bec30a SHA-1: 25c447a8a71a1a99d55b29cb3977f1839e767cd2 SHA-256: 8b9c843aaab3c360687d88cfdda24d1d8561e1a2a00e509cefaa644a3e2892db
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF contains a large number of links, many pointing to compromised CMS upload directories or disposable hosting, indicating a link farm designed to distribute malicious content. The ML classifier and ClamAV detection strongly suggest malicious intent, likely related to phishing or malware delivery via these external links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9976

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://mhinflatable.com/upload/file/muvibuvipavobes.pdf In PDF document text
    • http://www.fsnn.se/wp-content/plugins/formcraft/file-upload/server/content/files/1612efb4eea3bf---27632907971.pdfIn PDF document text
    • http://cabini.it/userfiles/files/wixitufululob.pdfIn PDF document text
    • http://chelseafoodmart.com/uploads/files/69738851106.pdfIn PDF document text
    • http://mikomisushi.com/uploads/files/wazarozajitisaxobomom.pdfIn PDF document text
    • http://studioarclab.eu/userfiles/files/sijeziwekanososusekamu.pdfIn PDF document text
    • https://ailani.org/wp-content/plugins/super-forms/uploads/php/files/b27117562470b79403d0edd43b3f2c7e/fefefodiwezasuwuf.pdfIn PDF document text
    • http://hrjok.com/uploadfile/file/5775177818.pdfIn PDF document text
    • http://bilcafe.it/userfiles/file/radeg.pdfIn PDF document text
    • https://ijfbacknumber.com/editor_up/982132600.pdfIn PDF document text
    • http://xn----7sbqwxdbhblh2h.xn--p1ai/data/file/86978437228.pdfIn PDF document text
    • http://laihoawedding.com/app/webroot/upload/files/pavijosu.pdfIn PDF document text
    • http://studiomalpocher.it/userfiles/files/31057516515.pdfIn PDF document text
    • https://mobile-translator.eu/app/webroot/media/files/gewiviwovor.pdfIn PDF document text
    • http://tech-in.info/bramy/userfiles/file/jedusiritovigaxados.pdfIn PDF document text
    • http://www.icf-plant.com/files/file/74793971972.pdfIn PDF document text
    • http://www.mbk-montage.nl/ckfinder/userfiles/files/27450480379.pdfIn PDF document text
    • https://larustt.com/upload/ckfinder/files/dedat.pdfIn PDF document text
    • http://asude.istanbul/ck_images/files/toxavejeg.pdfIn PDF document text
    • http://tnslib.tools/userfiles/files/54384823041.pdfIn PDF document text
    • https://holcom-wd.holcom.vn/webroot/img/files/fujisuruvujivoxogigez.pdfIn PDF document text
    • http://drvision.org/wp-content/plugins/formcraft/file-upload/server/content/files/16133176796b13---kotunelijunabit.pdfIn PDF document text
    • https://www.carlosfunes.es/wp-content/plugins/formcraft/file-upload/server/content/files/1612f73fada4ff---73268434473.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/ngfLrbzwjls/uplcv?utm_term=how+to+find+own+number+on+androidPDF 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_off0000bd22.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBD22 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000d534.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD534 16288 bytes
SHA-256: 6aaebb6960df18c5bd1fa78018f4cbb80772d867fb93712ab56097a2c020bafb
font_02_sfnt_off0000fe83.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFE83 10620 bytes
SHA-256: c4d1dea9f98704f005bf6e22798c50a92f469e375f2a7b3008803953dcb63da8