Malicious PDF — malware analysis report

Static analysis result for SHA-256 5d4d082af4253b3a…

MALICIOUS

PDF

67.4 KB Created: 2021-04-22 14:46:58 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-05-29
MD5: e4b86c8145d85d794e5d51355fad09f0 SHA-1: 15a19c02e13fab47bf445fd9d2696bc9a008f3fe SHA-256: 5d4d082af4253b3a092b2706b66ef37a7ef6f5baff1d887631e22a3c12773eba
126 Risk Score

Malware Insights

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

The sample was detected as a malicious PDF by ClamAV and an ML classifier. It contains numerous embedded URLs, many of which point to potentially compromised websites or link farms, suggesting an attempt to redirect users. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' indicates a tactic of using multiple distinct hosts for redirection, often seen in phishing campaigns.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

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/gmawards2018/45910982832.pdf In PDF document text
    • https://ambrose.edu/sites/default/files/webform/11364316539.pdfIn PDF document text
    • https://grossenbacher.co.nz/en/system/files/avoidance-training-certificates/pidefukil.pdfIn PDF document text
    • https://www.pharoxglobal.com/sites/default/files/webform/6669476875.pdfIn PDF document text
    • http://klm3fg.grhosting.cz/sites/default/files/webform/files/6948618973.pdfIn PDF document text
    • https://www.osgeurope.com/sites/osg-corporate.dev/files/webform/gurasijam.pdfIn PDF document text
    • https://www.jsif.org/sites/default/files/webform/meratasadif.pdfIn PDF document text
    • https://ambrose.edu/sites/default/files/webform/52499587618.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/~3/3CAf4wW3hvY/uplcv?utm_term=how+to+set+up+time+on+g+shock+5146PDF link annotation
    • https://drones.princeton.edu/system/files/webform/94207829768.pdfIn PDF document text
    • https://printandmail.princeton.edu/system/files/webform/98467125123.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_off0000c9e1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC9E1 5544 bytes
SHA-256: e1d008c3349fbc1f2cad5585dde4ed3b51f65bfb01e4873c03916ba33b724d06
font_01_sfnt_off0000dcce.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDCCE 10724 bytes
SHA-256: 908805ea34eef8afed4e339223d43c4497ea4ab9434832a75a60649a06947017