Malicious PDF — malware analysis report

Static analysis result for SHA-256 a7de5c621e6584fe…

MALICIOUS

PDF

80.3 KB Created: 2021-10-05 17:16:21 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: b2dbc206c50924c1e4c4e34d8867df90 SHA-1: 63c66c174856172c6ecbf8eaebab69a8e88679e8 SHA-256: a7de5c621e6584fe0da2cace846b2a41799336a36999469977e7fbd057a40385
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF file detected as malicious by ClamAV and ML classifiers. It contains embedded JavaScript and a link farm pointing to various domains, some of which appear to be compromised WordPress sites. The presence of embedded JavaScript suggests an attempt to execute malicious code, likely to facilitate further exploitation or download of additional payloads. The link farm structure indicates a phishing or redirection attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9960

Heuristics 7

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • PDF link farm points to compromised-WordPress upload storage medium PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM
    PDF contains multiple clickable links, across many distinct hosts, whose targets are random-slug files parked in the upload directories of vulnerable WordPress form plugins (FormCraft, Super Forms). This is the hallmark of the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains hosted on compromised sites. The PDF itself carries no exploit — the risk is the linked destinations.
  • 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.
  • 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 http://daejonggyoyc.com/userfiles/file/20210914084503.pdf
    • http://medica-eg.com/userfiles/file/tejizuwezatofixokade.pdf
    • https://altsovmun.ru/userfiles/file/nujino.pdf
    • http://uniradioweb.info/userfiles/files/talesovojovugexoku.pdf
    • https://egf.tw/test2/images/file/tigibodazuwivamedovipirax.pdf
    • https://nolimitscenter.be/peausitive/images/FCKeditor/file/xipemevozid.pdf
    • http://wccflooring.com/userfiles/files/ravekulejuzoguniguzerajir.pdf
    • http://kapfenberger-schuetzenverein.at/userfiles/file/vaxigadivanogefevexejeb.pdf
    • https://kurishupally.org/userfiles/file/97477230946.pdf
    • https://hpx.com.ua/wp-content/plugins/super-forms/uploads/php/files/190e0ae299eabc93c028606845c48186/jujuwejiremo.pdf
    • https://cosanuesa.com/componentes/editor/ckfinder/userfiles/files/79087463687.pdf
    • http://kccmaul.com/files/files/gifirezaliduv.pdf
    • http://macro-e.com/app/webroot/userfiles/files/75303220655.pdf
    • http://sun-eko.eu/files/file/97294215651.pdf
    • http://cps-mbstu.edu.bd/app/webroot/js/ckfinder/userfiles/files/rujarirogejekivibazegemes.pdf
    • http://www.ezmoving.com/file/nawapisegalipuveponura.pdf
    • http://www.radiopopiatej.com/wp-content/plugins/formcraft/file-upload/server/content/files/16138a2fdb8933---zufetevowuzujomu.pdf
    • https://almuhja.ps/ckfinder/userfiles/files/bupidibidilubewolevonufef.pdf
    • http://dorapeyzaj.com/userfiles/file/71705116741.pdf
    • http://texmet.pl/userimages/file/26997596073.pdf
    • http://fs-select.com/images/blog/file/86325432130.pdf
    • https://hantverkarenisandby.se/UserFiles/files/1486237697.pdf
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/16155d1e2c10c5---mogokur.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/PmAiG5ZyT-k/uplcv?utm_term=objective+of+preamble
    • 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://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000d534.bin
d047d28901ca900a1298581955966df38d2baa7a987655a09c6b35a12c423011
pdf-font-stream PDF embedded font (sfnt) at offset 0xD534 10728 bytes
font_01_sfnt_off0000eda7.bin
d6e0178f78ddda376314b45d04d5f742ccecb23a187071cfa114348a23db6acc
pdf-font-stream PDF embedded font (sfnt) at offset 0xEDA7 17752 bytes
font_02_sfnt_off00011c09.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x11C09 16792 bytes