Malicious PDF — malware analysis report

Static analysis result for SHA-256 3831711b248bf980…

MALICIOUS

PDF

73.5 KB Created: 2021-04-08 15:27:34 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-05-26
MD5: f1fcf970f2ee4355e98115131b39b136 SHA-1: 46b6db707406928b1dc635baa444b127905571d8 SHA-256: 3831711b248bf980948ff7101e09de09d2696112f7d5bd1216cacfc8e2a0e6f2
126 Risk Score

Malware Insights

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

The PDF file was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, directing users to various domains, one of which is `ambrose.edu`. The presence of embedded URLs and the overall structure suggest an attempt to redirect users to potentially malicious content, likely for phishing or malware distribution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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 https://ambrose.edu/sites/default/files/webform/58234525485.pdf In PDF document text
    • https://www.jwico.com/sites/default/files/webform/71926652616.pdfIn PDF document text
    • https://ambrose.edu/sites/default/files/webform/bunovodedodasu.pdfIn PDF document text
    • https://www.natsihwa.org.au/sites/default/files/webform/doxuwekuwazomiloxeri.pdfIn PDF document text
    • https://www.telluridescience.org/sites/default/files/tstc-applications/kuvusuwube.pdfIn PDF document text
    • https://www.jwico.com/sites/default/files/webform/49109440539.pdfIn PDF document text
    • https://www.jsif.org/sites/default/files/webform/meratasadif.pdfIn PDF document text
    • https://www.natsihwa.org.au/sites/default/files/webform/17947704001.pdfIn PDF document text
    • https://www.jwico.com/sites/default/files/webform/monufugabezexi.pdfIn PDF document text
    • https://www.visitsavannah.com/sites/default/files/webform/90994069376.pdfIn PDF document text
    • https://ambrose.edu/sites/default/files/webform/9027254294.pdfIn PDF document text
    • https://www.osgeurope.com/sites/osg-corporate.dev/files/webform/kanuvanirarotugawabu.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/~3/3vuEKuznOb8/uplcv?utm_term=adobe+photoshop+lightroom+cc+tutorials+pdfPDF link annotation
    • https://thesanfordschool.asu.edu/sites/default/files/webform/31460711967.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_off0000e0dd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE0DD 5700 bytes
SHA-256: f46108d1524114846a2bafc2fcdfae01e5322507c33153617a97d84a08598de5
font_01_sfnt_off0000f416.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF416 10820 bytes
SHA-256: ba865697c8af3c6ea6b3a348731563a59ace4346d6f3b4be22bfacb60d068954