Malicious PDF — malware analysis report

Static analysis result for SHA-256 576d92cc73ad086f…

MALICIOUS

PDF

67.9 KB Created: 2021-04-22 00:30:25 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-05-29
MD5: dcea13404b9ce9faad5403a420f0e205 SHA-1: 5d3e296c10740e39a2480451470aa93cb76ca62e SHA-256: 576d92cc73ad086f9967f1d556dab81c7a81861ed0199d11bc34d253ce0981cd
126 Risk Score

Malware Insights

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

The PDF contains numerous embedded links, many pointing to potentially malicious domains, and is flagged by ML classifiers and ClamAV as malicious. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' indicates a tactic to obscure malicious links within a large number of seemingly legitimate ones. While no scripts were explicitly extracted, the presence of external URIs and the overall detection suggest a phishing or malware distribution attempt.

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 https://grossenbacher.co.nz/en/system/files/avoidance-training-certificates/4264017636.pdf In PDF document text
    • http://klm3fg.grhosting.cz/sites/default/files/webform/files/nuzutigurazuleziwuta.pdfIn PDF document text
    • http://www.birdlifebotswana.org.bw/sites/default/files/webform/sightings-sketches/lewuxevibonotokezesa.pdfIn PDF document text
    • https://www.mainephilanthropy.org/sites/default/files/79141676299.pdfIn PDF document text
    • https://natsihwa.org.au/sites/default/files/webform/mufuwujaxerafesa.pdfIn PDF document text
    • https://www.uts.cw/sites/default/files/webform/pugixenarewowu.pdfIn PDF document text
    • https://ambrose.edu/sites/default/files/webform/61928937085.pdfIn PDF document text
    • https://www.mothercare.ro/sites/default/files/webform/resumes/77861868930.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/~3/3vuEKuznOb8/uplcv?utm_term=how+to+calculate+the+magnetic+field+strengthPDF link annotation
    • https://drones.princeton.edu/system/files/webform/66931006591.pdfIn PDF document text
    • https://printandmail.princeton.edu/system/files/webform/50156150340.pdfIn PDF document text
    • https://www.healthdata.org/sites/default/files/resumes/53082175038.pdfIn PDF document text
    • https://minorsoncampus.princeton.edu/system/files/webform/jawugu.pdfIn PDF document text
    • https://drones.princeton.edu/system/files/webform/voretazejujuwewoz.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_off0000cba1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCBA1 5488 bytes
SHA-256: f903ade2cf837f896c80e9b9f926443dcaeab2256a9ea3e43e21d8d5a705bfed
font_01_sfnt_off0000de33.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDE33 10648 bytes
SHA-256: d35ec02f51079438bc8b7b138ef3d2965da159f74213cb481038986c94bef10d