Malicious PDF — malware analysis report

Static analysis result for SHA-256 79aa8db5fedd8ae4…

MALICIOUS

PDF

82.4 KB Created: 2021-04-19 04:03:56 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-05-22
MD5: 5ce8ace9c45317fd5e038145884ac2a1 SHA-1: 1463e45ef0362e2223cf7dd271776a56ad478d87 SHA-256: 79aa8db5fedd8ae42740c670a406d9412f8513b1c2863fa729231c5d7a793d8c
126 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, with one heuristic specifically identifying it as a link farm on disposable hosting. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or distributing further malware. Although no scripts were extracted, the PDF structure and embedded links suggest an attempt to redirect the user to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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 http://www.grotekeukens.be/sites/default/files/webform/gmawards2018/87706268510.pdf In PDF document text
    • https://grossenbacher.co.nz/en/system/files/avoidance-training-certificates/4264017636.pdfIn PDF document text
    • https://extranet.blanchisserie-toulousaine-de-sante.com/sites/extranet.blanchisserie-toulousaine-de-sante.com/files/documents/justificatifs/vawutudujenopudup.pdfIn PDF document text
    • http://pilgrimland.com/sites/default/files/webform/resume-uploads/41345860665.pdfIn PDF document text
    • https://www.termis.org/system/files/webform/manejuwavujegajejumoxak.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/~3/3vuEKuznOb8/uplcv?utm_term=tokyo+ghoul+season+1+summaryPDF link annotation
    • https://campusrec.princeton.edu/system/files/webform/jelozubunumi.pdfIn PDF document text
    • https://drones.princeton.edu/system/files/webform/zifogisabivaloxigisosobu.pdfIn PDF document text
    • https://www.vub.be/sites/vub/files/webform/rifavuzido.pdfIn PDF document text
    • https://lib.asu.edu/system/files/webform/90369837207.pdfIn PDF document text
    • https://community.princeton.edu/system/files/webform/jidubiziro.pdfIn PDF document text
    • https://www.ice.cam.ac.uk/sites/www.ice.cam.ac.uk/files/webform/46273532178.pdfIn PDF document text
    • https://lib.asu.edu/system/files/webform/liwubuwivak.pdfIn PDF document text
    • https://gradfutures.princeton.edu/system/files/webform/xafuzekimizitigemuseli.pdfIn PDF document text
    • https://printandmail.princeton.edu/system/files/webform/zupedofijemurak.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 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000d119.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD119 16200 bytes
SHA-256: e1aea774af5697d24c9113b5313b82ea2171a038d7b378d1228b2aab78eabaa6
font_01_sfnt_off0001052d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1052D 5268 bytes
SHA-256: 6c74a0ca7d2f8e443c9c9ccbebfed1c04cd579ef0ed9db2ba44ac3cac1e7c2c4
font_02_sfnt_off00011702.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11702 11280 bytes
SHA-256: 54c0adee428f928c0f105de8b164bbf815629904e851b38c6a21eae83ea27588