Malicious PDF — malware analysis report

Static analysis result for SHA-256 a87b2780b435c72c…

MALICIOUS

PDF

84.6 KB Created: 2021-09-03 20:49:31 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: b30ad7355e4d41c705c66b6cc305a10c SHA-1: 1b4eb60fea944a273c62818cc888a25064ecadd5 SHA-256: a87b2780b435c72ce5445561d1fb2413c189ef6280c7733a69ba8865d9522664
156 Risk Score

Malware Insights

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

The PDF contains a link farm directing to multiple external URLs, some hosted on compromised CMS platforms. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or SEO abuse. No scripts were extracted, but the presence of numerous external links suggests the document's primary purpose is to redirect users to potentially harmful sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://revize-elektro.info/UserFiles/File/67222543019.pdf In PDF document text
    • https://wecareu.net/ckfinder/userfiles/files/71844029239.pdfIn PDF document text
    • https://ludifrance.fr/userfiles/file/pupupilubupopagojudatofaw.pdfIn PDF document text
    • https://www.baileysmilk.com/wp-content/plugins/super-forms/uploads/php/files/362338606fa09fcb65e9bb750471dc75/gamibob.pdfIn PDF document text
    • https://husvagnsexpo.se/wp-content/plugins/formcraft/file-upload/server/content/files/160f4a5246c64b---30551433133.pdfIn PDF document text
    • http://lhsclassof68.com/clients/73441/File/11187718978.pdfIn PDF document text
    • http://faxik.online/ckfinder/userfiles/files/rixelokop.pdfIn PDF document text
    • http://chixue.com/uploadfile/file/20210624085859.pdfIn PDF document text
    • https://www.growxponential.com/wp-content/plugins/super-forms/uploads/php/files/b2aq4kjn3t3lmnsl2mkfkuu61d/2616486210.pdfIn PDF document text
    • http://southportrubbish.com/wp-content/plugins/formcraft/file-upload/server/content/files/16074160abce63---katalefugugalumepuxawov.pdfIn PDF document text
    • http://18554080.com/userfiles/file/rinibik.pdfIn PDF document text
    • https://costabravas.com/uploads/localidades/files/wodejot.pdfIn PDF document text
    • http://abacusnancy.com/userfiles/file/13286888169.pdfIn PDF document text
    • http://stigstudiotecnico.it/userfiles/files/76747127919.pdfIn PDF document text
    • https://tripleccompanies.com/wp-content/plugins/super-forms/uploads/php/files/9c323e59c40d61f8f3f4d704ec8d2e2f/fowediretosiluwam.pdfIn PDF document text
    • http://mmbc.cz/_data/user_files/file/tevanebizusax.pdfIn PDF document text
    • https://www.verpoort-bouw.be/wp-content/plugins/formcraft/file-upload/server/content/files/160c5341eda353---16177775079.pdfIn PDF document text
    • http://sadiqandsons.com/userfiles/files/diduwozoguvijemugerazo.pdfIn PDF document text
    • https://stradatextiles.com/upload/ckfinder/files/54236730800.pdfIn PDF document text
    • http://sinostandards.net/upload/files/70205939162.pdfIn PDF document text
    • http://www.hkwebdesign.com.hk/wp-content/plugins/formcraft/file-upload/server/content/files/160a14c2f0f21a---88964115683.pdfIn PDF document text
    • https://proektasis.gr/admin/spaw2/uploads/files/jeraruforewinaxutadit.pdfIn PDF document text
    • http://china-miyaco.com/img/file/20216196193.pdfIn PDF document text
    • http://www.iqubz.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606f961ee9bb9---41527722563.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/cv9VXjIrmdE/uplcv?utm_term=sansui+9090+owners+manualPDF 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_off0000df36.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDF36 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f74d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF74D 10724 bytes
SHA-256: db5556f3ce9899fc4570de80c5cb03bd99c48fa6e3683d400afc29df3b36f3a6
font_02_sfnt_off00010ff1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10FF1 20252 bytes
SHA-256: 8cde818226b0c6da70e0be1ea7a039d65c5e5e316aebf3dca1f7a8d9f4e06265