Malicious PDF — malware analysis report

Static analysis result for SHA-256 b921717a1b8ac9d9…

MALICIOUS

PDF

63.8 KB Created: 2021-04-11 02:38:24 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-08-25
MD5: 517e1681dae60e83072a38efa247cfb2 SHA-1: 93a4f7b641960b1a3f1b4cb0d4959f5f21df251a SHA-256: b921717a1b8ac9d9e01962f1a36765319306498b2f2aea3275c4b8b995878072
124 Risk Score

Malware Insights

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

The PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. The document body, though heavily obfuscated, suggests a lure related to a 'final judgment' document. The presence of numerous external links, many pointing to potentially compromised or disposable domains, further supports a phishing or link-farming attack pattern. No scripts were extracted, but the PDF structure itself is indicative of malicious activity.

Machine Learning

  • Nyx PDF Classifier malicious score 0.8354

Heuristics 4

  • 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
  • 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://www.pbttphtk.gov.my/sites/default/files/webform/31626011693.pdf In PDF document text
    • https://www.dgs-interparts.be/sites/default/files/jinez.pdfIn PDF document text
    • http://www.friendlycc.com/sites/default/files/webform/tojatovovezugunubi.pdfIn PDF document text
    • https://extranet.blanchisserie-toulousaine-de-sante.com/sites/extranet.blanchisserie-toulousaine-de-sante.com/files/documents/justificatifs/6659556688.pdfIn PDF document text
    • http://portal-mysigma.com/system/files/student-proof/47432021317.pdfIn PDF document text
    • https://www.jwico.com/sites/default/files/webform/pagijan.pdfIn PDF document text
    • http://oaklandchildcare.org/sites/default/files/webform/veser.pdfIn PDF document text
    • https://vectorcorp.net/sites/default/files/webform/resume/sowasipaxezok.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/Uplcv/~3/fzgW7-mxBc0/uplcv?utm_term=juicio+final+john+katzenbach+pdfPDF link annotation
    • https://printandmail.princeton.edu/system/files/webform/83605599331.pdfIn PDF document text
    • https://thesanfordschool.asu.edu/sites/default/files/webform/43157208480.pdfIn PDF document text
    • https://lib.asu.edu/system/files/webform/liwubuwivak.pdfIn PDF document text
    • https://www.ice.cam.ac.uk/sites/www.ice.cam.ac.uk/files/webform/8342566550.pdfIn PDF document text
    • https://www.ice.cam.ac.uk/sites/www.ice.cam.ac.uk/files/webform/50075528518.pdfIn PDF document text
    • https://minorsoncampus.princeton.edu/system/files/webform/zotatati.pdfIn 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_off0000cb91.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCB91 5288 bytes
SHA-256: 611d287d0a37e181fabfb73b25772ae9529698b28df93639b4436c1535865d12
font_01_sfnt_off0000dd9a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDD9A 10680 bytes
SHA-256: 2090a9a1546cfb4f0005d510e7095229e6cb76cd4367124c8f1f17cd35e2aa9e