Malicious PDF — malware analysis report

Static analysis result for SHA-256 387ff7489ea32fa7…

MALICIOUS

PDF

71.1 KB Created: 2021-04-16 21:03:06 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-06-30
MD5: a52bb520de63e1ee6ba5733997b2ba80 SHA-1: 54f5af9b86e41ae05525bc07504b75c08a309c41 SHA-256: 387ff7489ea32fa76c170210a9a15ca5c504aed19c0acc2f514ade005f185074
126 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many of which point to domains that appear to be used for hosting malicious content, disguised as legitimate file uploads. The ML classifier and ClamAV detection strongly indicate malicious intent, likely related to phishing or malware delivery via a link farm. No scripts were extracted, but the structure suggests a lure to external resources.

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 http://pilgrimland.com/sites/default/files/webform/resume-uploads/64296936159.pdf In PDF document text
    • http://cicatsalud.com/html/sites/default/files/webform/24974410021.pdfIn PDF document text
    • http://russian-ice-spb.ru/sites/default/files/webform/files/69309865186.pdfIn PDF document text
    • http://www.grotekeukens.be/sites/default/files/webform/gmawards2018/45910982832.pdfIn PDF document text
    • http://www.guninetwork.org/system/files/webform/heirri_proposals/80098342864.pdfIn PDF document text
    • https://www.pharoxglobal.com/sites/default/files/webform/80628544521.pdfIn PDF document text
    • http://spotlight-sites.com/sites/default/files/webform/wokasonexigugeb.pdfIn PDF document text
    • https://www.mainephilanthropy.org/sites/default/files/79141676299.pdfIn PDF document text
    • http://www.sumnercountyhospital.org/sites/default/files/webform/27017481005.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/YTWXjIUwRh0/uplcv?utm_term=how+to+measure+off+a+pdfPDF link annotation
    • https://thesanfordschool.asu.edu/sites/default/files/webform/85266863194.pdfIn PDF document text
    • https://lib.asu.edu/system/files/webform/liwubuwivak.pdfIn PDF document text
    • https://drones.princeton.edu/system/files/webform/65601020807.pdfIn PDF document text
    • https://drones.princeton.edu/system/files/webform/61493424170.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_off0000da9f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDA9F 5208 bytes
SHA-256: d91bc109d63477579cd6d5999638745e0d6420f39c239af6d63be0921cf87998
font_01_sfnt_off0000ec4d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEC4D 10392 bytes
SHA-256: 12683dfb796286c9c9b0b4924083082ac3f8129f84f65bd416f4b6de9e5dae18