Malicious PDF — malware analysis report

Static analysis result for SHA-256 a881aa8a040035fc…

MALICIOUS

PDF

75.4 KB Created: 2021-05-01 15:25:08 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-07-13
MD5: e95b8e360718e89d85a45b1ecb290209 SHA-1: 4362b265b6721c90a09988b1d473d17ec4f634e6 SHA-256: a881aa8a040035fcf13bb7a82201a17feafe62fc010d39f9b05379a7fc2bb03e
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF document contains numerous external links, many of which point to compromised WordPress sites. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or distributing further malware. The presence of a link farm on disposable hosting and compromised CMS uploads suggests an effort to obscure the ultimate destination or leverage existing infrastructure for malicious purposes.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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 https://sharzh-ufa.ru/wp-content/plugins/super-forms/uploads/php/files/768c4937a60dd401c6703d4dad3ffdbb/detodegi.pdf In PDF document text
    • https://sckprime.com/wp-content/plugins/super-forms/uploads/php/files/187b615f3263f12be0d01d969dfa9679/79944967694.pdfIn PDF document text
    • http://akkoryazilim.com/userfiles/file/16263306996.pdfIn PDF document text
    • http://www.radiopopiatej.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607c5a9ddd3af---vewiladudajunurikovediwul.pdfIn PDF document text
    • https://asaptransfers.co.uk/wp-content/plugins/super-forms/uploads/php/files/5belkj1l6cjknr3mmugkh7qrv7/zabavo.pdfIn PDF document text
    • https://loan-financial.com/wp-content/plugins/super-forms/uploads/php/files/e74336d594542e2ca7b0ce1776a17755/91544596371.pdfIn PDF document text
    • http://www.mvdisposal.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607784e725aed---deribokunorobatugekokabi.pdfIn PDF document text
    • https://thejinglelab.com/wp-content/plugins/super-forms/uploads/php/files/f97npdd1m4pn53rk82c8q7thbi/61577172905.pdfIn PDF document text
    • http://www.cargeacrew.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160755719bbf99---10067992633.pdfIn PDF document text
    • https://sellerflows.com/wp-content/plugins/super-forms/uploads/php/files/2894bcb11813d35bc145a3b9413e9a30/15845682992.pdfIn PDF document text
    • http://www.caribbeandentist.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606d3be16189b---redodiporefa.pdfIn PDF document text
    • http://www.sg-callenberg.de/wp-content/plugins/formcraft/file-upload/server/content/files/1606c849ba157c---vagodikixe.pdfIn PDF document text
    • https://acethamessecurity.co.uk/wp-content/plugins/super-forms/uploads/php/files/7f2550e81e27f6989f04f7d2d10a1901/vefuvidafe.pdfIn PDF document text
    • https://gaseg.com/wp-content/plugins/super-forms/uploads/php/files/ifp1e6paf8k1d4sv3tevahaqqt/zotenapawoxasetigopik.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/BvfzZFkJO3s/uplcv?utm_term=biology+resource+book+sinhala+translationPDF 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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000e84b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE84B 5416 bytes
SHA-256: c46ce36b8f11c7374c8c8e2d360d8729b836d7c0b59388d95c7ebd209c23d705
font_01_sfnt_off0000fac3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFAC3 10716 bytes
SHA-256: 7c853d1cbef26df1fc1710771bc91efb93a1beb68a5804645e4ac113d556c498