Malicious PDF — malware analysis report

Static analysis result for SHA-256 027f93b87fc868a8…

MALICIOUS

PDF

35.0 KB Created: 2020-08-28 07:32:35 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: b8a27f71b499db9bffe285aa2c191acb SHA-1: 088c7b2686f85248233079d2cadbe9bca8a2cc36 SHA-256: 027f93b87fc868a8a2a006789ebca92ede8e097767366a7df9d3c2829f358326
154 Risk Score

Malware Insights

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

The PDF contains numerous embedded links, with one specifically pointing to a known malicious redirector. The document body, though partially obfuscated, includes text related to 'spanish worksheets' and the tool 'wkhtmltopdf', suggesting a lure to disguise malicious redirection. The ML classifier strongly flagged this PDF as malicious, supporting the conclusion that it's designed to lead users to harmful content.

Machine Learning

  • Nyx PDF Classifier malicious score 1.0000

Heuristics 4

  • PDF links to known malicious redirector infrastructure critical PDF_MALICIOUS_REDIRECTOR_LINK
    PDF contains a clickable URI to redirector infrastructure used by a known malicious PDF SEO/adware delivery campaign. These documents typically rely on user interaction and redirect chains rather than a PDF parser vulnerability.
  • Small PDF contains mass external PDF link farm critical PDF_SEO_LINK_FARM
    Small PDF contains many clickable external PDF links, mostly clustered on one host. This matches generated SEO/link-farm PDF carriers used to route users into malicious or unwanted-software delivery chains, rather than a normal document citation pattern.
  • 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://ttraff.com/pify?keyword=preterite+tense+in+spanish+worksheets
    • http://files.sectournaments.com/uploads/1/3/1/4/131452942/duzidakiwir-lewov-namel-ganamuda.pdf
    • http://kijopobo.kellymichellebaker.com/uploads/1/3/0/8/130874679/5673650.pdf
    • http://files.weatherfordobgyn.com/uploads/1/3/0/7/130739398/90048.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • https://cdn.shopify.com/s/files/1/0432/1057/1940/files/bjp_candidate_list_2020_maharashtra_election_download.pdf
    • https://cdn.shopify.com/s/files/1/0433/8922/3066/files/35730894768.pdf
    • https://cdn.shopify.com/s/files/1/0431/5670/1346/files/dunojawan.pdf
    • https://cdn.shopify.com/s/files/1/0438/8379/0491/files/student_exploration_calorimetry_lab_answers_activity_a.pdf
    • https://cdn.shopify.com/s/files/1/0433/0687/7080/files/90262961418.pdf
    • https://cdn.shopify.com/s/files/1/0428/9835/8432/files/13578549785.pdf
    • https://cdn.shopify.com/s/files/1/0428/7099/7151/files/90675853847.pdf
    • https://cdn.shopify.com/s/files/1/0438/9902/7611/files/kegujexiguwazob.pdf
    • https://cdn.shopify.com/s/files/1/0437/1428/1625/files/license_plate_template_texas.pdf
    • https://cdn.shopify.com/s/files/1/0438/9021/3019/files/amrita_nayak_new_odia_song_2019.pdf
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://scripts.sil.org/OFL

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00004af9.bin
5afcfe1906007745c2ebcdc2ddf168f9f625320db5babf6c708e9b235d08aa31
pdf-font-stream PDF embedded font (sfnt) at offset 0x4AF9 5032 bytes
font_01_sfnt_off00005c15.bin
bb87f6459db6771789d8bd0c3e46f233a3fec65b3ef3f6d47df7dd026d9b9274
pdf-font-stream PDF embedded font (sfnt) at offset 0x5C15 10300 bytes