Malicious PDF — malware analysis report

Static analysis result for SHA-256 d559f7eb1b7d0132…

MALICIOUS

PDF

82.3 KB Created: 2021-04-16 21:52:56 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-05-29
MD5: c1cbbc2ea255d7df80431d0bc66e4f09 SHA-1: cbac2a460cf3ac88e1406cf2f3a889dd06ad8ba4 SHA-256: d559f7eb1b7d01323380bb29867fbdb3fb599b363eb8f14d1cffc77b1856f021
126 Risk Score

Malware Insights

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

The PDF file was flagged by multiple heuristics, including a critical ClamAV detection and an ML classifier indicating maliciousness. It contains numerous embedded URLs, many of which point to disposable domains or link farms, suggesting a phishing or credential harvesting attempt. The presence of 'wkhtmltopdf' in the metadata and the nature of the URLs suggest it may be used to redirect users to malicious sites.

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 https://web.liderpapel.com/sites/default/files/webform/wavunivuzabanovomid.pdf In PDF document text
    • https://www.woonsocketri.org/system/temporary/webform/konoju.pdfIn PDF document text
    • https://www.cdcplumbing.com/sites/default/files/webform/contact-us/65589142167.pdfIn PDF document text
    • https://www.a1touchsolution.nl/sites/default/files/dovav.pdfIn PDF document text
    • http://www.pbttphtk.gov.my/sites/default/files/webform/238550972.pdfIn PDF document text
    • https://aboss.by/sites/default/files/webform/vobefoxejajizagosoberob.pdfIn PDF document text
    • https://europa-ts.ru/sites/default/files/webform/sujeludepotunebimetoravij.pdfIn PDF document text
    • https://www.pharoxglobal.com/sites/default/files/webform/zomufajiwadusepa.pdfIn PDF document text
    • https://www.termis.org/system/files/webform/98565071062.pdfIn PDF document text
    • https://www.jwico.com/sites/default/files/webform/47965191786.pdfIn PDF document text
    • https://grossenbacher.co.nz/en/system/files/avoidance-training-certificates/22559513310.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/~3/1xuhb7AK25c/uplcv?utm_term=what+to+the+slave+is+the+fourth+of+july+importancePDF link annotation
    • https://ec.europa.eu/eip/agriculture/sites/default/files/webform/66140853426.pdfIn PDF document text
    • https://www.healthdata.org/sites/default/files/resumes/mavesoriv.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_off00010285.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10285 5508 bytes
SHA-256: 90911ab7b6f2f8d75b5d99a76c1f5bd32204ed12a622626827f07abea9787cae
font_01_sfnt_off00011532.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11532 11840 bytes
SHA-256: 37a7a9881c17b6d25a79e58c6c919d3e84898c81a8f9af2c3a15d0989c053876