Malicious PDF — malware analysis report

Static analysis result for SHA-256 d36d04cf1e2d7474…

MALICIOUS

PDF

95.6 KB Created: 2021-04-15 15:48:57 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-05-29
MD5: 344773004fd431bc4a3fada72510eb55 SHA-1: cc8cee087b8df95ade3b95a2019cd86dbda51878 SHA-256: d36d04cf1e2d7474fc43a13ea6d7d72440db3cc22eee6eab93343b71c90f2a0c
126 Risk Score

Malware Insights

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

The PDF was flagged by ML classifiers and ClamAV as malicious, with heuristics indicating it functions as a link farm on disposable hosting. The embedded URLs, despite some being marked benign, point to a pattern of redirecting users to potentially malicious sites. No scripts were extracted, but the overall structure and heuristic firings suggest an attempt to lure users to external content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

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 http://cicatsalud.com/html/sites/default/files/webform/25507329945.pdf In PDF document text
    • https://www.natsihwa.org.au/sites/default/files/webform/17423244846.pdfIn PDF document text
    • http://oaklandchildcare.org/sites/default/files/webform/1289321409.pdfIn PDF document text
    • https://www.enwidth.com/sites/default/files/webform/resumes/palepipob.pdfIn PDF document text
    • http://oaklandchildcare.org/sites/default/files/webform/26688185713.pdfIn PDF document text
    • https://www.a1touchsolution.nl/sites/default/files/tarutemivejumariwara.pdfIn PDF document text
    • https://www.afscme65.org/system/files/webform/52844377902.pdfIn PDF document text
    • https://www.telluridescience.org/sites/default/files/tstc-applications/90077644064.pdfIn PDF document text
    • http://www.pbttphtk.gov.my/sites/default/files/webform/nolukaronedibikix.pdfIn PDF document text
    • https://www.pharoxglobal.com/sites/default/files/webform/6669476875.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://www.daltonmaag.com/In PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/3CAf4wW3hvY/uplcv?utm_term=what+is+basic+theory+of+interestPDF link annotation
    • https://printandmail.princeton.edu/system/files/webform/ziwilijevugibapuvoboka.pdfIn PDF document text
    • https://www.vub.be/sites/vub/files/webform/fazarixi.pdfIn PDF document text
    • https://www.ice.cam.ac.uk/sites/www.ice.cam.ac.uk/files/webform/10713621665.pdfIn PDF document text
    • https://www.vub.be/sites/vub/files/webform/lijulur.pdfIn PDF document text
    • https://minorsoncampus.princeton.edu/system/files/webform/kuwidiloj.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 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00012b32.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12B32 4980 bytes
SHA-256: 7dd74ee94ec50f4845dec43d9b9d2234cc6153f3a70c4a45addb2c17de3c4836
font_01_sfnt_off00013c18.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13C18 11052 bytes
SHA-256: 0cb82b5303dbefc19e9b7c5fa0b233fbf8279a8ec86e9df47059a6df9dde31af
font_02_sfnt_off000161ba.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x161BA 4324 bytes
SHA-256: 0d0f64e27578eb124b8bc81c7eceacdd166e22eddd95c81328e9fbd7de2a6333