Malicious PDF — malware analysis report

Static analysis result for SHA-256 707b9eb261dcbb4e…

MALICIOUS

PDF

82.4 KB Created: 2021-04-25 13:03:06 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-05-29
MD5: 48ec552eabfb6cebc9125715a849297d SHA-1: 56d2a81893477967990ac157c1515cc14745d051 SHA-256: 707b9eb261dcbb4e8332f17870bba583ed486651ad9434ab5decd4a3921bc4f3
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

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, containing numerous embedded URLs pointing to various domains. The document body, though heavily obfuscated, contains metadata suggesting it was generated by wkhtmltopdf, a tool often used to create PDFs from web content, further supporting the link farm hypothesis.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9996

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://natsihwa.org.au/sites/default/files/webform/46250275999.pdf In PDF document text
    • https://grossenbacher.co.nz/en/system/files/avoidance-training-certificates/basolidigululaba.pdfIn PDF document text
    • https://www.natsihwa.org.au/sites/default/files/webform/setafemamuf.pdfIn PDF document text
    • http://cicatsalud.com/html/sites/default/files/webform/foxegedukob.pdfIn PDF document text
    • https://www.mothercare.ro/sites/default/files/webform/resumes/topijetidilotifoga.pdfIn PDF document text
    • http://oaklandchildcare.org/sites/default/files/webform/dakorudi.pdfIn PDF document text
    • https://www.mothercare.ro/sites/default/files/webform/resumes/xigidaz.pdfIn PDF document text
    • http://www.pbttphtk.gov.my/sites/default/files/webform/88462653206.pdfIn PDF document text
    • https://www.enwidth.com/sites/default/files/webform/resumes/48862039041.pdfIn PDF document text
    • http://www.pbttphtk.gov.my/sites/default/files/webform/nolukaronedibikix.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/~3/1xuhb7AK25c/uplcv?utm_term=purpose+generic+structure+and+language+feature+of+descriptive+textPDF link annotation
    • https://printandmail.princeton.edu/system/files/webform/ziwilijevugibapuvoboka.pdfIn PDF document text
    • https://printandmail.princeton.edu/system/files/webform/31356988355.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
    • 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_off0000ed4b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xED4B 5452 bytes
SHA-256: 0be5406bb55832578d14e651307a0fbd21bbcf04e84023d31fc1a6be2843cd19
font_01_sfnt_off0000ffef.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFFEF 10680 bytes
SHA-256: e107eee342c7b5d46177a59bd5ea944dc75380dbf9d6233da957fefd77d95491
font_02_sfnt_off000124a9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x124A9 16204 bytes
SHA-256: c988415812f594187b0a0ed75dc52802e798e1695b49bd300f8412a65040a449

Open this report in the interactive analyzer, or submit your own file for analysis.