Malicious PDF — malware analysis report

Static analysis result for SHA-256 731e9bbbd1bb281a…

MALICIOUS

PDF

76.6 KB Created: 2021-04-18 00:07:42 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-05-29
MD5: 9a9a4a2926d7eead3328148acc751985 SHA-1: b34db10381dbb96e042ea3b022f84d8378e67e80 SHA-256: 731e9bbbd1bb281a36d9c79323a89cddb8cdf60e0044e5fc1deda90af8980aec
126 Risk Score

Malware Insights

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

The PDF was flagged by ML and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, directing users to multiple distinct domains, one of which is associated with a disposable host. While no scripts were directly extracted, the PDF structure and embedded URLs suggest an attempt to redirect users to malicious content, likely for phishing or malware delivery.

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://europa-ts.ru/sites/default/files/webform/6529842099.pdf In PDF document text
    • https://www.natsihwa.org.au/sites/default/files/webform/86947183128.pdfIn PDF document text
    • https://ambrose.edu/sites/default/files/webform/padubomi.pdfIn PDF document text
    • http://oaklandchildcare.org/sites/default/files/webform/ponezilineg.pdfIn PDF document text
    • https://aboss.by/sites/default/files/webform/tatesejozamelifat.pdfIn PDF document text
    • https://www.afscme65.org/system/files/webform/rerezuduzolorefa.pdfIn PDF document text
    • https://www.a1touchsolution.nl/sites/default/files/larigujumikanezazezogiwi.pdfIn PDF document text
    • https://www.newburghgroup.com/sites/default/files/webform/resumes/41319995155.pdfIn PDF document text
    • https://www.pharoxglobal.com/sites/default/files/webform/balulata.pdfIn PDF document text
    • https://www.blplegal.com/sites/default/files/webform/25596831819.pdfIn PDF document text
    • http://www.pbttphtk.gov.my/sites/default/files/webform/zoxajetuvu.pdfIn PDF document text
    • https://www.jsif.org/sites/default/files/webform/rijuluzevowogadabiwi.pdfIn PDF document text
    • http://russian-ice-spb.ru/sites/default/files/webform/files/fapulewamekunasu.pdfIn PDF document text
    • https://www.enwidth.com/sites/default/files/webform/resumes/wefegazeketalewawer.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/PmAiG5ZyT-k/uplcv?utm_term=how+to+use+a+ps2+controller+on+ps3+without+adapterPDF link annotation
    • https://printandmail.princeton.edu/system/files/webform/26360011081.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_off0000ec09.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEC09 5508 bytes
SHA-256: 3bbb9cfabbb0271273d53370ae9aa17956361cd66bf2e7d04d0f1f55932154cc
font_01_sfnt_off0000fecc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFECC 11280 bytes
SHA-256: b0b50ef27b641de56f2490c7ebe8d845ef5d9e9ff0dca2786072be37f4e66274