Malicious PDF — malware analysis report

Static analysis result for SHA-256 da79541cfb06c1aa…

MALICIOUS

PDF

69.3 KB Created: 2021-04-09 06:58:20 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-05-29
MD5: a7da7c4ffd0fe3af3aab175a9e596027 SHA-1: 96fe0fc904aee49daa43a2122f0a563dad179d92 SHA-256: da79541cfb06c1aa66d41d09ab03a940bfe3d43db9bffdcc07930be1c3fce312
126 Risk Score

Malware Insights

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

The PDF file was detected as malicious by ML classifiers and ClamAV, indicating a phishing or trojan payload. The presence of numerous embedded URLs, many pointing to disposable or unknown domains, suggests a link farm designed to obscure the ultimate malicious destination. While no scripts were explicitly extracted, the PDF structure and heuristic firings point towards a phishing lure, likely intended to deliver a second-stage payload.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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://www.muttypawsacademy.com/sites/default/files/webform/vaccines/95859103094.pdf In PDF document text
    • https://www.osgeurope.com/sites/osg-corporate.dev/files/webform/kanuvanirarotugawabu.pdfIn PDF document text
    • https://ambrose.edu/sites/default/files/webform/74647609277.pdfIn PDF document text
    • https://natsihwa.org.au/sites/default/files/webform/degajakuko.pdfIn PDF document text
    • http://www.guninetwork.org/system/files/webform/heirri_proposals/rarapenebeku.pdfIn PDF document text
    • http://www.muttypawsacademy.com/sites/default/files/webform/vaccines/72246142748.pdfIn PDF document text
    • https://www.telluridescience.org/sites/default/files/tstc-applications/nuwirofu.pdfIn PDF document text
    • http://www.grotekeukens.be/sites/default/files/webform/gmawards2018/84972388600.pdfIn PDF document text
    • http://www.pbttphtk.gov.my/sites/default/files/webform/88462653206.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=uae+calendar+2018+with+holidays+pdfPDF link annotation
    • https://ec.europa.eu/eip/agriculture/sites/default/files/webform/95830943344.pdfIn PDF document text
    • https://lib.asu.edu/system/files/webform/98562832035.pdfIn PDF document text
    • https://ec.europa.eu/eip/agriculture/sites/default/files/webform/72323592377.pdfIn PDF document text
    • https://lib.asu.edu/system/files/webform/dilitopuwivane.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_off0000cfd1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCFD1 5948 bytes
SHA-256: 7516a8612823f81100bd861de9ff09522695dd863fba353aff76618942bb55fe
font_01_sfnt_off0000e429.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE429 11000 bytes
SHA-256: 374da7545210b677f64b3505c06a24160693456ebd9ae1f547e38347963e414f