Malicious PDF — malware analysis report

Static analysis result for SHA-256 31168e26d4784d7b…

MALICIOUS

PDF

90.9 KB Created: 2021-08-08 09:53:32 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: b47529e80ed1ac3ad420628fe645b146 SHA-1: 40a63cab92a01dd220ff1a628206b98c15ae4eee SHA-256: 31168e26d4784d7b0749e069e392c5393ad1b273ba143f8dc1561eeaf85437d3
156 Risk Score

Malware Insights

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

The PDF file was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. It contains numerous links, many pointing to compromised WordPress sites or disposable domains, suggesting it's designed to lead users to malicious content. The document body is heavily obfuscated and appears to be generated by wkhtmltopdf, providing no direct user-facing lure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9970

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 http://humanlitech.com/files/files/waxijexa.pdf In PDF document text
    • http://alpha-cp.com/userfiles/file/82793321612.pdfIn PDF document text
    • https://ortechindustries.ca/ci/userfiles/files/68195809344.pdfIn PDF document text
    • https://pluviaterra.mx/wp-content/plugins/super-forms/uploads/php/files/beae4d06245abfb29c4754f227b26d7d/12878512250.pdfIn PDF document text
    • https://betenenergy.com/sites/default/files/file/13737046178.pdfIn PDF document text
    • https://advancedcheckcashadvance.com/wp-content/plugins/formcraft/file-upload/server/content/files/16096deed84a28---65874434206.pdfIn PDF document text
    • http://www.atrium-tuiles.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608783749ba40---voxopetenojemepeb.pdfIn PDF document text
    • https://www.lumisolar.pe/wp-content/plugins/formcraft/file-upload/server/content/files/16098df64430cf---nimutu.pdfIn PDF document text
    • https://3dreamstudios.com/wp-content/plugins/super-forms/uploads/php/files/fef8cbc8f97901c95bd3321c429704e0/jigofovovonivewef.pdfIn PDF document text
    • http://kpotplace.com/uploads/files/pawazojewek.pdfIn PDF document text
    • http://ecbpolska.pl/wp-content/plugins/super-forms/uploads/php/files/72c606c8f1afd910418ebd51774e336f/59275175842.pdfIn PDF document text
    • https://vanchuyenduongsat.vn/upload/files/maviruno.pdfIn PDF document text
    • https://alshaabcoop.com/userfiles/file/71045578440.pdfIn PDF document text
    • https://www.tangelo.no/wp-content/plugins/formcraft/file-upload/server/content/files/160848608e9d5a---44394025810.pdfIn PDF document text
    • http://pmdrecycling.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ac34bee2a4f---99073231077.pdfIn PDF document text
    • https://www.superioreagle.com/wp-content/plugins/formcraft/file-upload/server/content/files/16098f9bfbce78---nunefokem.pdfIn PDF document text
    • http://lws-realestate.com/userfiles/files/39431990060.pdfIn PDF document text
    • https://www.plsok.com/wp-content/plugins/super-forms/uploads/php/files/61a48fd5d4e8a33c6ecb3696c7030323/62766697113.pdfIn PDF document text
    • http://www.drop-lok.com/wp-content/plugins/formcraft/file-upload/server/content/files/16085283ce8cf6---fuzij.pdfIn PDF document text
    • https://www.tctnanotech.com/wp-content/plugins/super-forms/uploads/php/files/a6fa5ed7d4428d74c3ce380b1f621c12/98263103665.pdfIn PDF document text
    • https://semineebrasov.ro/printuri-fi/files/68547623912.pdfIn PDF document text
    • https://macleanpinesdrivingschool.com.au/wp-content/plugins/super-forms/uploads/php/files/40041cf315040d01903d584a5eb252aa/61906380971.pdfIn PDF document text
    • https://chambres-hotes-aube-bleue.fr/userfiles/file/naxasixifojupasig.pdfIn PDF document text
    • https://sindonis.com/userfiles/file/50590465151.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/cv9VXjIrmdE/uplcv?utm_term=who+is+the+best+3+point+shooter+in+the+nba+2020PDF 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_off0000fefc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFEFC 10848 bytes
SHA-256: 6233297afefc968fe164d0a37e093436853799f205fcf60f297c1c10c845919d
font_01_sfnt_off000117dd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x117DD 16908 bytes
SHA-256: 7fd1104d623f1f57726b30432d7b36e0619b2b6b3a0dfac353e5ecbf36c37c20
font_02_sfnt_off00014430.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x14430 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1