Malicious PDF — malware analysis report

Static analysis result for SHA-256 88b2171b040fb211…

MALICIOUS

PDF

80.4 KB Created: 2021-07-18 03:32:55 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-08-20
MD5: e714504397a098e76b418a63a30a9d51 SHA-1: afce382f7cbcdc091869694ea59102fe14963d3b SHA-256: 88b2171b040fb2110bb50c87612d28a2c93435fcbbdab1c90fef9f16d1453621
136 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file was detected as malicious by ClamAV and an ML classifier, with high-severity heuristics indicating it contains a redirector link designed for phishing. The PDF's structure and embedded URLs suggest an attempt to lure users to a site that likely hosts a phishing form or further malicious content. No scripts were extracted, but the overall pattern points to a phishing campaign.

Machine Learning

  • Nyx PDF Classifier malicious score 0.6556

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
  • Image lure linking to an SEO redirector (free-download phishing) high PDF_SEO_UTM_REDIRECTOR_LINK
    PDF embeds an image with little or no body text and a clickable link to a multi-word utm_term / FeedBurner-proxied SEO redirector — the 'free ebook / solution-manual / document download' phishing family that ranks for natural-language search queries and routes the user into a payload/redirect chain. The PDF carries no exploit; the risk is the linked destination. Flagged structurally (image lure + SEO redirector) so it does not depend on a ClamAV/ML signature, and regardless of how many filler text pages the lure carries.
  • 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://feedproxy.google.com/~r/sq/ugae/~3/0YvHz_IItD0/square?utm_term=add+watermark+to+pdf+online+free PDF link annotation
    • https://static1.squarespace.com/static/60bf6c89a2b0b938881bcf91/t/60f35664c5d9e6782ce1d6a5/1626560101094/calculate_the_heat_of_combustion_of_ethene.pdfIn PDF document text
    • https://static1.squarespace.com/static/60bf6c89a2b0b938881bcf91/t/60f333f2d9389f5e808c60e0/1626551282511/conditional_type_0_1_2_3.pdfIn PDF document text
    • https://static1.squarespace.com/static/60aac59fb7e9621e2f466549/t/60f36a0ccba7b71501e7c062/1626565133409/find_answers_to_riddles.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://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000da0c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDA0C 16636 bytes
SHA-256: aa9b9da36f91383a85ce42830971d73fb21a6a68e985beb8da447e5ef17d626a
font_01_sfnt_off0001056e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1056E 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00011d85.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11D85 10648 bytes
SHA-256: 3611e80aa2b6fa3b694a5804830fb9e6a2af128e81775639976fd4edca4ff1c2