Malicious PDF — malware analysis report

Static analysis result for SHA-256 42553927297ef850…

MALICIOUS

PDF

72.1 KB Created: 2021-04-09 07:54:07 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-07-13
MD5: ac0478b224b790f39526610a2168bcc6 SHA-1: 0233094008adb03850bd586203ba4329d3db5829 SHA-256: 42553927297ef850563595fed7498b4b2d5a3dff9775a64322c8cae0a98a52c5
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The PDF contains numerous embedded URLs, many of which point to disposable domains and are structured to appear as legitimate documents, such as budget reports. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or to serve a secondary payload. While no scripts were explicitly extracted, the PDF structure and embedded links suggest an attempt to redirect the user to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://portal-mysigma.com/system/files/student-proof/72808970040.pdf In PDF document text
    • https://grossenbacher.co.nz/en/system/files/avoidance-training-certificates/pidefukil.pdfIn PDF document text
    • https://www.osgeurope.com/sites/osg-corporate.dev/files/webform/nutuzisujobipusife.pdfIn PDF document text
    • http://klm3fg.grhosting.cz/sites/default/files/webform/files/vewamilobofesiwukor.pdfIn PDF document text
    • https://ambrose.edu/sites/default/files/webform/61928937085.pdfIn PDF document text
    • http://russian-ice-spb.ru/sites/default/files/webform/files/loxigexaxezirizedud.pdfIn PDF document text
    • https://ambrose.edu/sites/default/files/webform/talizovub.pdfIn PDF document text
    • http://spotlight-sites.com/sites/default/files/webform/93789740410.pdfIn PDF document text
    • http://spotlight-sites.com/sites/default/files/webform/sugugijokasu.pdfIn PDF document text
    • http://cicatsalud.com/html/sites/default/files/webform/61943826361.pdfIn PDF document text
    • https://www.natsihwa.org.au/sites/default/files/webform/setafemamuf.pdfIn PDF document text
    • http://seiary.com/sites/default/files/webform/rec/jizexatunurometubukos.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/6naE_Nh8_CY/uplcv?utm_term=2019+budget+sri+lanka+in+tamil+pdfPDF link annotation
    • https://www.healthdata.org/sites/default/files/resumes/78922999772.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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000db9f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDB9F 5952 bytes
SHA-256: 313608626274c74b186db1abce6d04f39cd8cd7456ffe52788667bf251e2d572
font_01_sfnt_off0000efc5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEFC5 10656 bytes
SHA-256: 2a79ee1f98a3bd165b8c0a897d9d2b97ec14c270da2adda08f5f8770abb98645