Malicious PDF — malware analysis report

Static analysis result for SHA-256 a9a61d483c33cb51…

MALICIOUS

PDF

73.6 KB Created: 2021-04-21 22:45:37 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-06-30
MD5: 4c6cb4390a5b25f422d9ab3d32f71cd8 SHA-1: 5463b0d06ed95823eba7e13b571cb0c6f3769cfb SHA-256: a9a61d483c33cb510e8cb95d75e5453dab4567469ddafb5be1ba33398d350968
126 Risk Score

Malware Insights

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

The PDF file was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. The heuristics indicate it functions as a link farm, directing users to multiple external websites, some of which are hosted on disposable domains. While no scripts were explicitly extracted, the PDF structure and the nature of the heuristics suggest an attempt to redirect users to malicious content, likely through embedded JavaScript or other exploit mechanisms.

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://web.liderpapel.com/sites/default/files/webform/xikamiwaboloz.pdf In PDF document text
    • https://ambrose.edu/sites/default/files/webform/zabufenopi.pdfIn PDF document text
    • https://web.liderpapel.com/sites/default/files/webform/dojoxopanikofogenag.pdfIn PDF document text
    • http://www.pbttphtk.gov.my/sites/default/files/webform/vojazasazobixupolaxi.pdfIn PDF document text
    • https://www.ofalloncasting.com/sites/default/files/webform/dapajinosez.pdfIn PDF document text
    • https://www.jsif.org/sites/default/files/webform/nozixedexifanozavarojiro.pdfIn PDF document text
    • http://www.birdlifebotswana.org.bw/sites/default/files/webform/sightings-sketches/beporu.pdfIn PDF document text
    • https://www.natsihwa.org.au/sites/default/files/webform/42406093886.pdfIn PDF document text
    • http://pilgrimland.com/sites/default/files/webform/resume-uploads/woluweweketasuzizolog.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/BkSY9tpko7c/uplcv?utm_term=graco+nautilus+65+lx+limitsPDF link annotation
    • https://community.princeton.edu/system/files/webform/setokan.pdfIn PDF document text
    • https://drones.princeton.edu/system/files/webform/65601020807.pdfIn PDF document text
    • https://printandmail.princeton.edu/system/files/webform/31356988355.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_off0000e453.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE453 5320 bytes
SHA-256: 142397fafe6870d25f2c1cfebdf01739537b48ba2acd75d60b2d1c9a587643b4
font_01_sfnt_off0000f660.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF660 10508 bytes
SHA-256: 51deaba0132513acf5f044aaf7e0583e4ca6a08031abf5570c9cf812d293e348