Malicious PDF — malware analysis report

Static analysis result for SHA-256 73b50da9d45429fa…

MALICIOUS

PDF

71.7 KB Created: 2021-04-02 02:45:41 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 29e4a971b99b9d1d1aaeccee7a45d518 SHA-1: 13092a1f7a860f0af97c6571982972739f040ae7 SHA-256: 73b50da9d45429fa18b5a5061279488e6c07579e7224ec8beb4c4d22cc056155
156 Risk Score

Malware Insights

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

The PDF file was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. It contains a large number of external links, with one pointing to a suspicious domain 'vilenefex.ru'. While no scripts were explicitly extracted, the PDF structure and the presence of numerous external links suggest an attempt to redirect users to malicious sites, potentially for phishing or malware distribution. The document body was heavily obfuscated and unreadable.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

Heuristics 5

  • 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.
  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://vilenefex.ru/strik?utm_term=what+is+the+art+of+communication+defined+as
    • http://centerbluebadge.com/tamil_songs_starmusiq_2014sx2dy.pdf
    • http://vulifux.66ghz.com/lymphatic_system_anatomy.pdf
    • https://tajerupabud.weebly.com/uploads/1/3/1/1/131164315/xikosurix.pdf
    • https://falojabuvo.weebly.com/uploads/1/3/4/7/134774067/f23867df331f.pdf
    • https://nudikiwo.weebly.com/uploads/1/3/4/0/134042489/8045915.pdf
    • https://xagigerabep.weebly.com/uploads/1/3/1/4/131483632/ddf83fb4.pdf
    • http://infonewstravel.com/think_and_grow_rich_pantip3ablf.pdf
    • https://sipedevete.weebly.com/uploads/1/3/1/4/131438766/e5f29825f56014.pdf
    • http://storeeuro.info/how_to_insert_bobbin_singer_sewing_machinezk1y7.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • https://s3.amazonaws.com/zomuzigo/car_alternator_working_principle.pdf
    • https://s3.amazonaws.com/medaliwifufugel/best_ferrari_testarossa.pdf
    • https://s3.amazonaws.com/xugigabitulu/77456154879.pdf
    • https://s3.amazonaws.com/nowokil/cant_get_key_out_of_ignition_dead_battery.pdf
    • http://bopatazemot.rf.gd/15871727150.pdf
    • https://s3.amazonaws.com/remeranexe/zexefoso.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_off0000dfda.bin
411fc5ee222a0582d8618f1732ced0e83ad15ea4adbbc711cd9591b666b1e691
pdf-font-stream PDF embedded font (sfnt) at offset 0xDFDA 5244 bytes
font_01_sfnt_off0000f18f.bin
c209211aa97daf3262f1d99f102c6ac5b0c56b3f412c2f1f1fa5611031746946
pdf-font-stream PDF embedded font (sfnt) at offset 0xF18F 9464 bytes