Malicious PDF — malware analysis report

Static analysis result for SHA-256 2d99d7c927a536e0…

MALICIOUS

PDF

71.2 KB Created: 2021-04-06 18:55:38 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-05-29
MD5: 0861e48d9edcd54c678326fa61b98662 SHA-1: 23f1eb98f7379a0d766288f4adb5c1877d6e7af5 SHA-256: 2d99d7c927a536e0b8a559a15aa73b5499e743544dd57440ac0fc8a6e885488f
126 Risk Score

Malware Insights

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

The PDF document contains numerous external links, many of which are hosted on disposable domains and appear to be part of a link farm, a common tactic for phishing or malware distribution. The ML classifier and ClamAV detection strongly indicate malicious intent. While no scripts were explicitly extracted, the PDF structure and heuristic firings suggest it is designed to redirect users to potentially harmful websites.

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 https://aboss.by/sites/default/files/webform/zivexovoburowunaxomenip.pdf In PDF document text
    • https://www.natsihwa.org.au/sites/default/files/webform/72789215659.pdfIn PDF document text
    • http://www.sumnercountyhospital.org/sites/default/files/webform/sixativitav.pdfIn PDF document text
    • https://www.enwidth.com/sites/default/files/webform/resumes/90018929780.pdfIn PDF document text
    • http://www.friendlycc.com/sites/default/files/webform/topevonizudurazot.pdfIn PDF document text
    • https://www.osgeurope.com/sites/osg-corporate.dev/files/webform/14219433733.pdfIn PDF document text
    • https://www.cdcplumbing.com/sites/default/files/webform/contact-us/sawifujemenolezaf.pdfIn PDF document text
    • https://web.liderpapel.com/sites/default/files/webform/wavunivuzabanovomid.pdfIn PDF document text
    • http://pilgrimland.com/sites/default/files/webform/resume-uploads/69774832497.pdfIn PDF document text
    • http://klm3fg.grhosting.cz/sites/default/files/webform/files/56601188302.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://feedproxy.google.com/~r/Uplcv/~3/6naE_Nh8_CY/uplcv?utm_term=abruzzo+guida+turistica+pdfPDF link annotation
    • https://minorsoncampus.princeton.edu/system/files/webform/janoruzafasolefixos.pdfIn PDF document text
    • https://minorsoncampus.princeton.edu/system/files/webform/zotatati.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_off0000d674.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD674 5472 bytes
SHA-256: b180267bbbc3733b6bd08c96ac40c155ae98811c2a91df7e1ce88e3240eb7608
font_01_sfnt_off0000e928.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE928 11428 bytes
SHA-256: f828ce83d11e23d2f55999e768758f48be1703a678f84c85c9ee2d892e99c207