Malicious PDF — malware analysis report

Static analysis result for SHA-256 786ff3278f2dc863…

MALICIOUS

PDF

72.4 KB Created: 2021-04-15 16:57:35 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-05-23
MD5: d839ce322cc65f60c0ca8dad56f5115a SHA-1: 4a8f77cbbe493373dc2a64b9af503a5956f11e6e SHA-256: 786ff3278f2dc8635210beabb6771116674e221d752dc5271e2ae8c6c82120b5
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF file was flagged as malicious by a machine learning classifier and ClamAV, indicating a high likelihood of malicious intent. The PDF_SEO_DISPOSABLE_LINK_FARM heuristic and the numerous embedded URLs suggest the document is part of a link farm designed to attract traffic, likely for SEO poisoning or to distribute further malware. The document body contains text related to pairing TP-Link devices, which is likely a lure to disguise the malicious nature of the PDF.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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.friendlycc.com/sites/default/files/webform/topevonizudurazot.pdf In PDF document text
    • https://ambrose.edu/sites/default/files/webform/99544266771.pdfIn PDF document text
    • https://grossenbacher.co.nz/en/system/files/avoidance-training-certificates/3242210986.pdfIn PDF document text
    • https://natsihwa.org.au/sites/default/files/webform/17015803.pdfIn PDF document text
    • https://ambrose.edu/sites/default/files/webform/9027254294.pdfIn PDF document text
    • https://www.mothercare.ro/sites/default/files/webform/resumes/95866450710.pdfIn PDF document text
    • http://www.pacificsportfraservalley.com/sites/default/files/webform/93322629498.pdfIn PDF document text
    • https://architecturaldesigninc.com/sites/default/files/bujepalifomi.pdfIn PDF document text
    • http://russian-ice-spb.ru/sites/default/files/webform/files/32020734574.pdfIn PDF document text
    • https://www.a1touchsolution.nl/sites/default/files/73086307569.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/zMnd8XtcwSM/uplcv?utm_term=how+to+pair+tp+link+av1000PDF link annotation
    • https://drones.princeton.edu/system/files/webform/janewif.pdfIn PDF document text
    • https://lib.asu.edu/system/files/webform/dilitopuwivane.pdfIn PDF document text
    • https://lib.asu.edu/system/files/webform/85824103047.pdfIn PDF document text
    • https://minorsoncampus.princeton.edu/system/files/webform/jawugu.pdfIn PDF document text
    • https://printandmail.princeton.edu/system/files/webform/50156150340.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
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000ca66.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCA66 5004 bytes
SHA-256: c2286c5ca6d349450cc847875f65d27a9454700dd78f0420ea4229171e146d66
font_01_sfnt_off0000db93.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDB93 10476 bytes
SHA-256: 6c344a075e8165bd9771eb866f96bc115b3a6eb0e63e545ac5a71ecf9cf718b1
font_02_sfnt_off0000ff8e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFF8E 16140 bytes
SHA-256: 1ffca1ef16be5e2ec436e77f9211a88ad3199dc781cb76600401cc2e2c7dce6d

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