Malicious PDF — malware analysis report

Static analysis result for SHA-256 73ec253ba87a258b…

MALICIOUS

PDF

71.4 KB Created: 2020-12-21 21:26:17 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: dac669b08fe02c966382a23dac08e850 SHA-1: 16e3b363d7efd37017645135481ee5bbdec19c23 SHA-256: 73ec253ba87a258bec9370379f9fcb044a94dcf2d3be93b044da71fd346ed681
154 Risk Score

Malware Insights

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

The PDF file contains a link to a known malicious redirector, indicating a phishing attempt. The document body, though heavily obfuscated, suggests a lure related to retirement benefits ('kalkulator zus emerytura'). The ML classifier and ClamAV detection strongly support its malicious nature. No scripts were extracted, but the presence of a malicious URL is the primary indicator of compromise.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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.
  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://gettraff.ru/123?utm_term=kalkulator+zus+emerytura
    • https://cdn-cms.f-static.net/uploads/4413455/normal_5f96fdfe44501.pdf
    • https://cdn-cms.f-static.net/uploads/4453721/normal_5fb4553ad888b.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • https://s3.amazonaws.com/salade/69278328691.pdf
    • https://uploads.strikinglycdn.com/files/f76a1b11-9aa8-427a-9b84-0298404520df/74647498462.pdf
    • https://uploads.strikinglycdn.com/files/fb541955-980a-4dca-9317-40addf315a3e/pabitibidadurigevuxufev.pdf
    • https://s3.amazonaws.com/sazixipame/vawuveba.pdf
    • https://uploads.strikinglycdn.com/files/0ba4ac84-e567-4f3a-b555-20b0aa76e8a7/deadpool_2_streaming_hulu.pdf
    • https://uploads.strikinglycdn.com/files/c86f3ca4-9bb3-40ef-8695-33813315ef78/vunamorixopiwuxuwopezesaf.pdf
    • https://static1.squarespace.com/static/5fbce344be7cfc36344e8aaf/t/5fbf63615147b148042b2a1d/1606378338470/how_to_build_a_mob_grinder_1.15.pdf
    • https://s3.amazonaws.com/vetamedisoz/long_division_worksheets_grade_10.pdf
    • https://uploads.strikinglycdn.com/files/8e1d5c3e-6800-4f5b-b904-1bdde8c13f90/27611222680.pdf
    • https://s3.amazonaws.com/zabevog/images_of_kelly_nash.pdf
    • https://uploads.strikinglycdn.com/files/4deb3b82-1042-4b1a-ae46-13e10daad1bf/bdo_organic_feed_vs_good_feed.pdf
    • https://s3.amazonaws.com/posufij/55846207019.pdf
    • https://s3.amazonaws.com/wavunot/open_itunes_account_on_my_computer.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_off0000d939.bin
eb6f063646bb596bd26a315b0b844cd657ad5385d536b675a43be1afc770ff49
pdf-font-stream PDF embedded font (sfnt) at offset 0xD939 5016 bytes
font_01_sfnt_off0000ea42.bin
81f38b15755a4ffee48790ee472d8a36a0bfc3f0f02cd64aae337fe3ad8b0335
pdf-font-stream PDF embedded font (sfnt) at offset 0xEA42 11692 bytes