Malicious PDF — malware analysis report

Static analysis result for SHA-256 34601f0d842d25b4…

MALICIOUS

PDF

84.8 KB Created: 2021-09-12 23:04:02 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 678d1df4b0686e312da9188c983274e7 SHA-1: 120f2d466867d1277a0f44abd876e4cf28fe8a8a SHA-256: 34601f0d842d25b4bdce3a87a5562adf0111180783b54d75594d1cbe5635e801
142 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The sample is identified as malicious by ML classifiers and ClamAV, with heuristics indicating it is a link farm and uses an invoice lure. Embedded JavaScript streams suggest an attempt to execute code, likely to download a second-stage payload from one of the numerous external URLs. The document body, though heavily obfuscated, contains metadata from wkhtmltopdf, indicating it was likely generated programmatically.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9980

Heuristics 7

  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • Fake invoice / payment lure low SE_INVOICE_LURE
    Document contains invoice or payment language paired with an action verb — useful context when combined with link, macro, or attachment indicators
  • 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://carcable-bg.com/uploads/pictures/files/satixijon.pdf In PDF document text
    • http://idevicesplus.nl/app/webroot/files/userfiles/files/4827638023.pdfIn PDF document text
    • http://sk4education.com/ckfinder/userfiles/files/5410094459.pdfIn PDF document text
    • http://h04ydivan.ru/userfiles/file/6276739375.pdfIn PDF document text
    • http://osheamaloneynylaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/meberilip.pdfIn PDF document text
    • https://cafesca.info/ckfinder/userfiles/files/63020247535.pdfIn PDF document text
    • https://actorconseil.com/files/file/nevuw.pdfIn PDF document text
    • http://rotang.net/userfiles/file/6659912777.pdfIn PDF document text
    • https://www.tulsarad.com/my_content/js/ckfinder/userfiles/files/55990537482.pdfIn PDF document text
    • https://goez1.com/10005001208290177/ckfinder/userfiles/files/35511638311.pdfIn PDF document text
    • https://vibanghanoi.com/uploads/files/pumefesajuwu.pdfIn PDF document text
    • http://yilbasipromosyonu.com/userfiles/file/fixewewijen.pdfIn PDF document text
    • https://auf.vn/wp-content/plugins/super-forms/uploads/php/files/sd25nsgaossuh21i1v6q71oc63/49362893134.pdfIn PDF document text
    • http://kaizenlife.com/ckfinder/userfiles/files/41114935406.pdfIn PDF document text
    • http://atlantichomeportugal.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613d393b89256---jawebagabur.pdfIn PDF document text
    • https://silatur.com/js/ckfinder/userfiles/files/guluroteginos.pdfIn PDF document text
    • http://ieltsadd.ir/cache/fck_files/file/rekurarijez.pdfIn PDF document text
    • https://tese.in/ckfinder/userfiles/files/gumozajonamosera.pdfIn PDF document text
    • https://gtijsr.com/userfiles/file/segerofupunitowogukapegij.pdfIn PDF document text
    • http://debsecond.net/UserFiles/File/kasituravutino.pdfIn PDF document text
    • http://6nergy.fr/6nergy/sites/default/user/file/favejefosutafedi.pdfIn PDF document text
    • http://purofirstli.com/userfiles/files/60698781655.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/zMnd8XtcwSM/uplcv?utm_term=hidden+call+log+for+androidPDF link annotation
    • 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_off0000e7b6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE7B6 10376 bytes
SHA-256: e0cc67597dde54bc3f046e1f222fb90bd49ff960351a0e11bae164cc9349b206
font_01_sfnt_off0000feef.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFEEF 17916 bytes
SHA-256: fb41c96205233a856f5c3023836a062428fb14c8062e31eb076804f83b2de6c2
font_02_sfnt_off00012d2a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12D2A 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1