Malicious PDF — malware analysis report

Static analysis result for SHA-256 52c9826836e0fe88…

MALICIOUS

PDF

69.9 KB Created: 2021-04-20 11:47:39 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-05-29
MD5: 7e84282d8d51afd12995bb6ea474a4f7 SHA-1: 099a7ea08c2d5412544077b51e73124a9d555c22 SHA-256: 52c9826836e0fe883593608c2b0279c3bb435b470e04315093404634fb8f48ab
126 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many pointing to disposable domains, and is flagged by heuristics as a link farm. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or malware distribution. Although no scripts were explicitly extracted, the PDF structure and embedded links suggest an attempt to redirect the user to a malicious site, aligning with spearphishing tactics.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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 https://vectorcorp.net/sites/default/files/webform/resume/sabaw.pdf In PDF document text
    • https://www.enwidth.com/sites/default/files/webform/resumes/ralivowu.pdfIn PDF document text
    • https://www.blplegal.com/sites/default/files/webform/80507347088.pdfIn PDF document text
    • https://www.newburghgroup.com/sites/default/files/webform/resumes/falaburisidibiwad.pdfIn PDF document text
    • https://www.osgeurope.com/sites/osg-corporate.dev/files/webform/tajiwugebewozebukak.pdfIn PDF document text
    • http://www.muttypawsacademy.com/sites/default/files/webform/vaccines/40041164747.pdfIn PDF document text
    • https://www.natsihwa.org.au/sites/default/files/webform/25680057182.pdfIn PDF document text
    • http://www.muttypawsacademy.com/sites/default/files/webform/vaccines/nojezajewi.pdfIn PDF document text
    • https://web.liderpapel.com/sites/default/files/webform/wavunivuzabanovomid.pdfIn PDF document text
    • https://ambrose.edu/sites/default/files/webform/tinijozude.pdfIn PDF document text
    • https://www.a1touchsolution.nl/sites/default/files/43963154407.pdfIn PDF document text
    • http://www.friendlycc.com/sites/default/files/webform/tojatovovezugunubi.pdfIn PDF document text
    • http://www.friendlycc.com/sites/default/files/webform/74296331991.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/1eyvgo/aqOO/~3/A3Ryygt5BCM/uplcv?utm_term=john+deere+js63+enginePDF link annotation
    • https://community.princeton.edu/system/files/webform/36479690150.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_off0000d44d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD44D 5228 bytes
SHA-256: 62abe9e26d26e3e7a4a358543d091a57172a499f01633d7c4dee4a2b7d3a7f92
font_01_sfnt_off0000e613.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE613 10816 bytes
SHA-256: c0be593b13a31c0ce1d18a3c8de2786e4392c408f5453ea2e0cc30d3b9c9e0b5