Malicious PDF — malware analysis report

Static analysis result for SHA-256 b1a4e3a5962e31e1…

MALICIOUS

PDF

70.3 KB Created: 2021-04-19 03:57:30 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-27
MD5: 96f730fadc50afa69dbe80b7f40b6d84 SHA-1: ead170d812618c48c697012340a6e14e8d67a0fa SHA-256: b1a4e3a5962e31e135f429a859d69e2dd8ec6463edc0483b161ae00081e19879
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. Heuristics indicate it functions as a link farm, directing users to multiple external URLs. While no scripts were explicitly extracted, the PDF structure and the nature of the heuristics suggest potential for embedded malicious JavaScript or other exploits to facilitate phishing or malware delivery.

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://www.natsihwa.org.au/sites/default/files/webform/xugapovapoz.pdf In PDF document text
    • https://www.ofalloncasting.com/sites/default/files/webform/tirudekamevajoluzagobumi.pdfIn PDF document text
    • https://web.liderpapel.com/sites/default/files/webform/dojoxopanikofogenag.pdfIn PDF document text
    • https://web.liderpapel.com/sites/default/files/webform/wavunivuzabanovomid.pdfIn PDF document text
    • http://www.friendlycc.com/sites/default/files/webform/47778491084.pdfIn PDF document text
    • https://www.pharoxglobal.com/sites/default/files/webform/80628544521.pdfIn PDF document text
    • https://www.ofalloncasting.com/sites/default/files/webform/gegemapoxazokex.pdfIn PDF document text
    • http://www.sumnercountyhospital.org/sites/default/files/webform/sixativitav.pdfIn PDF document text
    • http://spotlight-sites.com/sites/default/files/webform/loboje.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/Uplcv/~3/1xuhb7AK25c/uplcv?utm_term=which+european+country+has+the+highest+gdpPDF link annotation
    • https://community.princeton.edu/system/files/webform/vujipudujusikal.pdfIn PDF document text
    • https://ec.europa.eu/eip/agriculture/sites/default/files/webform/77241298986.pdfIn PDF document text
    • https://thesanfordschool.asu.edu/sites/default/files/webform/87767597376.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_off0000d65c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD65C 5416 bytes
SHA-256: 1adc23be692602013ee678579dc55dabff6ba0d070aaef02370cb0ed8da4f0f8
font_01_sfnt_off0000e8d8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE8D8 10448 bytes
SHA-256: b4cc47093cbefc7d40245f76c28ba9bb6811a235a329bea894aa216a52bb3ec6