Malicious PDF — malware analysis report

Static analysis result for SHA-256 9b11a3f25ac1b817…

MALICIOUS

PDF

90.3 KB Created: 2021-04-19 22:35:46 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-05-26
MD5: a21e81613d42415c38b6b63a6805d678 SHA-1: 2e4636a4fb415f40ff015a81a0fc4ff0f1f4d82c SHA-256: 9b11a3f25ac1b817b7241178ebabe07c4f3f70f2769a7411e136cd430dc2a4e4
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, indicating a phishing or trojan payload. It contains a large number of embedded URLs, many of which point to potentially disposable domains or are part of a link farm, suggesting an attempt to redirect users to malicious sites. The document body, though heavily obfuscated, contains text related to the embedded URLs, reinforcing the lure.

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://www.woonsocketri.org/system/temporary/webform/bogobovimefegaf.pdf In PDF document text
    • http://oaklandchildcare.org/sites/default/files/webform/dakorudi.pdfIn PDF document text
    • https://ambrose.edu/sites/default/files/webform/sudelo.pdfIn PDF document text
    • http://www.grotekeukens.be/sites/default/files/webform/gmawards2018/30150103061.pdfIn PDF document text
    • http://www.pacificsportfraservalley.com/sites/default/files/webform/90877516301.pdfIn PDF document text
    • https://www.newburghgroup.com/sites/default/files/webform/resumes/falaburisidibiwad.pdfIn PDF document text
    • http://www.friendlycc.com/sites/default/files/webform/85881129832.pdfIn PDF document text
    • https://www.jts.org.jo/sites/default/files/webform/86196288468.pdfIn PDF document text
    • https://www.woonsocketri.org/system/temporary/webform/makepepatamizozixijefawop.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/DOqCt-cVA4I/uplcv?utm_term=read+this+passage+from+the+way+to+rainy+mountain+before+there+were+horsesPDF link annotation
    • https://printandmail.princeton.edu/system/files/webform/21250884575.pdfIn PDF document text
    • https://minorsoncampus.princeton.edu/system/files/webform/libovonudipiguriteg.pdfIn PDF document text
    • https://www.ice.cam.ac.uk/sites/www.ice.cam.ac.uk/files/webform/17420147243.pdfIn PDF document text
    • https://ec.europa.eu/eip/agriculture/sites/default/files/webform/9071701793.pdfIn PDF document text
    • https://www.vub.be/sites/vub/files/webform/lijulur.pdfIn PDF document text
    • https://community.princeton.edu/system/files/webform/36479690150.pdfIn PDF document text
    • https://lib.asu.edu/system/files/webform/46247033309.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_off0001238d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1238D 5764 bytes
SHA-256: d0dcf0dd1b42aec36d5a1e930b50a4dae165ef47ad96cef7ba1b4b499cf2d569
font_01_sfnt_off00013724.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13724 10676 bytes
SHA-256: b24e84cc338e121873636d0f2b8873c9c848fce06dea91fc4b9b5abd32253203