Malicious PDF — malware analysis report

Static analysis result for SHA-256 23426e827961853f…

MALICIOUS

PDF

81.9 KB Created: 2021-09-20 10:44:56 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: a076e2ef9546d3321613552355d6911b SHA-1: df1a8756edac5a4f6b29aad4dd0202dac8cebb40 SHA-256: 23426e827961853f2b8f9df718d5bed8ca8f2cf62a2dbb58ddc33c58019623c5
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF file was flagged by ClamAV as a phishing trojan and a machine learning classifier indicated a high probability of maliciousness. Heuristics identified it as a link farm, with many URLs pointing to compromised CMS uploads or disposable hosting, suggesting an attempt to distribute malicious content or phish users. The document body is heavily obfuscated and unreadable, providing no further context.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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.
  • 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://ministerium.pt/files/23321781730.pdf
    • https://brusroom.com/wp-content/plugins/super-forms/uploads/php/files/d8715e55a6cad0ed341520066d28ca31/rexizozugeselox.pdf
    • http://www.patriarca-batiment.com/ressource/site-image/files/sidevomoritow.pdf
    • https://www.emcp-pmce.ca/_includes/ckfinder/userfiles/files/soperedomuvap.pdf
    • http://chinalabware.net/d/files/kelojixebafo.pdf
    • https://pnp-studio.com/fckeditorfiles/file/makajefanatiliziligikolib.pdf
    • http://svsteinfurth.de/radsportfiles/file/83163200526.pdf
    • http://ahknchem.com/upload/files/butamefaragumuma.pdf
    • https://at2-turbo-j3t.com/contents/files/46774834907.pdf
    • http://thunderstar.cn/userfiles/file/20210910075501592764506.pdf
    • https://listapp.in/ci/userfiles/files/79587361196.pdf
    • https://sportsht.com/userfiles/file/51117518504.pdf
    • http://www.commandinglife.com/wp-content/plugins/formcraft/file-upload/server/content/files/161451cae14d0f---kedadixonanaposisatogine.pdf
    • http://paintingservicesonline.ca/wp-content/plugins/formcraft/file-upload/server/content/files/1614819445aa08---3426084954.pdf
    • http://nebovsem.ru/app/webroot/files/files/60622462840.pdf
    • http://homokkepek.hu/editor_up/fejeboke.pdf
    • https://rakbah.healthybitespk.com/alpha/ckfinder/userfiles/files/tizenuziwesobowozewemovej.pdf
    • https://cristalensi.com/public/File/ribipomutexozuwogilut.pdf
    • https://brianspradlin.com/userfiles/file/zapodixe.pdf
    • http://jdjcnc.com/upfolder/e/files/20210914052010.pdf
    • http://www.theflightfest.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613ae134ef111---fomiviveramogofa.pdf
    • http://langeline.com/ckeditor/upload/files/firagatanofekavupemivutif.pdf
    • http://buyyoutubesubscribers.com/ci/userfiles/files/48777301733.pdf
    • http://himalayakebab.com/shipinc/userfiles/files/26215231816.pdf
    • https://certifiedmoversinc.com/wp-content/plugins/super-forms/uploads/php/files/8b5fd2ead8b4919837eefef8cd9f6b0b/97102670792.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/PmAiG5ZyT-k/uplcv?utm_term=sword+art+online+memory+defrag+hack+apk
    • 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_off0000d71c.bin
632373e1c5526d4b0b256f2cd024d240d9ed6ff9d0ed22240b3e8cab52371d20
pdf-font-stream PDF embedded font (sfnt) at offset 0xD71C 11264 bytes
font_01_sfnt_off0000f138.bin
65cc5fb6312e3290c8e7589869d4cab253f356d207c65447219b8dac760034be
pdf-font-stream PDF embedded font (sfnt) at offset 0xF138 18700 bytes
font_02_sfnt_off000121b8.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x121B8 16792 bytes