Malicious PDF — malware analysis report

Static analysis result for SHA-256 4a2a638e1b58c046…

MALICIOUS

PDF

73.1 KB Created: 2021-04-27 01:44:17 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-12
MD5: acae9454d3896dddc13a6d2085b4b003 SHA-1: 09bac2c3a5ef3212b2aa114c559cf823f4b20e95 SHA-256: 4a2a638e1b58c046bcc390b4a2679edb9d695c1abb04756fb1dc0e33bf5f3f3a
126 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many pointing to disposable domains, and is flagged as a link farm. ClamAV detection and ML classification indicate malicious intent, likely phishing or malware distribution. The document body is heavily obfuscated and contains no clear textual lure.

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.muttypawsacademy.com/sites/default/files/webform/vaccines/lozege.pdf In PDF document text
    • http://spotlight-sites.com/sites/default/files/webform/40861703051.pdfIn PDF document text
    • https://www.pharoxglobal.com/sites/default/files/webform/zomufajiwadusepa.pdfIn PDF document text
    • http://www.friendlycc.com/sites/default/files/webform/zuguxinukebezukul.pdfIn PDF document text
    • https://www.osgeurope.com/sites/osg-corporate.dev/files/webform/gurasijam.pdfIn PDF document text
    • http://cicatsalud.com/html/sites/default/files/webform/93477879009.pdfIn PDF document text
    • https://web.liderpapel.com/sites/default/files/webform/dojoxopanikofogenag.pdfIn PDF document text
    • http://oaklandchildcare.org/sites/default/files/webform/80411930416.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/1eyvgo/aqOO/~3/ngfLrbzwjls/uplcv?utm_term=digital+design+subwoofer+boxPDF link annotation
    • https://www.healthdata.org/sites/default/files/resumes/68382108709.pdfIn PDF document text
    • https://drones.princeton.edu/system/files/webform/voretazejujuwewoz.pdfIn PDF document text
    • https://printandmail.princeton.edu/system/files/webform/42849177422.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_off0000debe.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDEBE 5376 bytes
SHA-256: f092e6b3ffe56157d2f7f52bbca25b885ed75ee392e065b97437eb777b857506
font_01_sfnt_off0000f12e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF12E 11416 bytes
SHA-256: 681a68d380c5d85867aec1c7792c71723ca68e797b59bc5050059b3b57c69eec