Malicious PDF — malware analysis report

Static analysis result for SHA-256 0e52831233c35bf9…

MALICIOUS

PDF

74.5 KB Created: 2021-06-10 10:33:36 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-21
MD5: 2a2b526b787f5fa357ae5fd840d3b71c SHA-1: a5f762c8e767a560fb3defefb6d4b76bfc8bdea2 SHA-256: 0e52831233c35bf992b2e18e1314ecc21682a633d9f304a8c1661288c2ddbc22
156 Risk Score

Malware Insights

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

The sample is identified as malicious by ML classifiers and ClamAV, indicating it's a phishing trojan. It leverages a link farm hosted on compromised WordPress sites, presenting a deceptive lure for a chess primer PDF to encourage downloads. The presence of external URIs and link farms suggests an attempt to redirect users to malicious content or download further stages.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

Heuristics 6

  • 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.
  • 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://chcial.ru/uplcv?utm_term=the+soviet+chess+primer+pdf+free+download PDF link annotation
    • https://torrentclub.vip/wp-content/plugins/super-forms/uploads/php/files/0in86sslj7ohc3ofag3ugilasg/92236909433.pdfIn PDF document text
    • http://harasim.cz/uploaded/files/8562177178.pdfIn PDF document text
    • https://www.reparaciondebomba.com.ar/wp-content/plugins/super-forms/uploads/php/files/6ncei4cphsd16i2el9oev7vah7/7904225070.pdfIn PDF document text
    • https://csom.cz/wp-content/plugins/super-forms/uploads/php/files/c94e2067234def11176f4c528f35d02f/zaboxofumewabimesiledul.pdfIn PDF document text
    • https://unitedcardsolutions.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609b393a137a8---lizibuted.pdfIn PDF document text
    • https://lcd96.ru/wp-content/plugins/super-forms/uploads/php/files/ad3a51b561967497fa0a0a985ed133ca/wapofupunujuw.pdfIn PDF document text
    • http://duancanhotot.com/upload/files/mujoxalozudiso.pdfIn PDF document text
    • http://visualpaint.com/wp-content/plugins/formcraft/file-upload/server/content/files/16092a9f179ba0---42495347391.pdfIn PDF document text
    • http://dso-fuzine.si/docs/vopojevifi.pdfIn PDF document text
    • https://idfusionllc.com/wp-content/plugins/super-forms/uploads/php/files/c87f8d5410c16c58832dad0af037df4a/pizupuxuzitavo.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b346963bfcd---50851692530.pdfIn PDF document text
    • https://www.arphplumbing.co.uk/wp-content/plugins/super-forms/uploads/php/files/20mivmrbiapqamhfrohmjd6pep/11235981553.pdfIn PDF document text
    • http://leap-egypt.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609cff209e8cb---16211220819.pdfIn PDF document text
    • http://sazjah.com/wp-content/plugins/formcraft/file-upload/server/content/files/16076d19b95dc5---48600373777.pdfIn PDF document text
    • https://www.napariverinn.com/wp-content/plugins/super-forms/uploads/php/files/bf5447e2ff3a54d08a6f2419d709ff2b/15477065679.pdfIn PDF document text
    • http://www.lbf-cosmetics.com/website/wp-content/plugins/formcraft/file-upload/server/content/files/16093b4f67b8a8---pakutonixomuwofof.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://www.daltonmaag.com/In PDF document text
    • 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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000d5a9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD5A9 5284 bytes
SHA-256: f0906f9c30917032155d065f938ab1fd5f40ce242ee31a681e740a5d0ab9484c
font_01_sfnt_off0000e793.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE793 11268 bytes
SHA-256: 9a6cd20844496c3fc1c287a2cdf168047de71442fe59ccee338ffbe570b7e5d7
font_02_sfnt_off00010cb1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10CB1 4324 bytes
SHA-256: ce7e2e230a41ba6fc2d7d2240890c8289d67876d84a3d076d67c0b48111c8230