Malicious PDF — malware analysis report

Static analysis result for SHA-256 3a7c43279f5a4549…

MALICIOUS

PDF

83.5 KB Created: 2021-04-26 14:07:01 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-05-29
MD5: 4bfb97131ab5a0d8902601666ce6669d SHA-1: 1616fcb2fe144ca76dc58283ee9347bda3034f44 SHA-256: 3a7c43279f5a454946a0efddb3a82a608e8133ec5976c215e092245c65646af4
126 Risk Score

Malware Insights

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

The PDF file was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. It contains numerous embedded URLs, many of which point to domains that are not yet classified, suggesting a link farm designed to redirect users. The presence of multiple external URIs and the 'PDF_SEO_DISPOSABLE_LINK_FARM' heuristic indicate a strong intent to lead users to potentially harmful 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://www.enwidth.com/sites/default/files/webform/resumes/48862039041.pdf In PDF document text
    • http://portal-mysigma.com/system/files/student-proof/tevesifisota.pdfIn PDF document text
    • https://www.natsihwa.org.au/sites/default/files/webform/42406093886.pdfIn PDF document text
    • https://www.natsihwa.org.au/sites/default/files/webform/17947704001.pdfIn PDF document text
    • https://www.osgeurope.com/sites/osg-corporate.dev/files/webform/zizepuniket.pdfIn PDF document text
    • http://pilgrimland.com/sites/default/files/webform/resume-uploads/mikax.pdfIn PDF document text
    • http://www.pbttphtk.gov.my/sites/default/files/webform/32056102714.pdfIn PDF document text
    • https://www.visitsavannah.com/sites/default/files/webform/nodarinit.pdfIn PDF document text
    • https://www.a1touchsolution.nl/sites/default/files/95216779236.pdfIn PDF document text
    • http://www.grotekeukens.be/sites/default/files/webform/gmawards2018/41850888982.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/cv9VXjIrmdE/uplcv?utm_term=cien+a%25C3%25B1os+de+soledad+resumen+corto+rincon+del+vagoPDF link annotation
    • https://thesanfordschool.asu.edu/sites/default/files/webform/lezedatabamivija.pdfIn PDF document text
    • https://lib.asu.edu/system/files/webform/simadovi.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_off000105ad.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x105AD 5436 bytes
SHA-256: 30d5eef4441342043fd9ec50f5ae815902af856c65955db95b827efea60c94ef
font_01_sfnt_off000117d1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x117D1 12088 bytes
SHA-256: 82d66510d04322377ebb70084cc061e914aba8cec5f3b4959b4e57cb7fc9b324