Malicious PDF — malware analysis report

Static analysis result for SHA-256 a842e87c0119c1a1…

MALICIOUS

PDF

67.9 KB Created: 2021-05-01 01:28:41 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-11
MD5: 5e07b1d2938a9aafe59e8a91e020a811 SHA-1: fd3a01e8d3059b106ae076cc4cda9bdc9495069a SHA-256: a842e87c0119c1a13abd524476c36e827fb3d49a963c62be8cb4371dbd273bce
156 Risk Score

Malware Insights

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

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. The PDF contains numerous links to external websites, many of which are hosted on compromised CMS uploads, suggesting a link farm or phishing lure. The document body, though heavily obfuscated, appears to relate to tax contributions, a common theme for phishing scams.

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://brylka-kfz.de/wp-content/plugins/formcraft/file-upload/server/content/files/160801e3d8659a---pewinadalolapesebi.pdf In PDF document text
    • https://jjmassociates.com/wp-content/plugins/super-forms/uploads/php/files/a78a6ec8ed7b6b71693d60c98a50ccc9/lowalozosotikejatemitaso.pdfIn PDF document text
    • http://www.melloecastro.com/wp-content/plugins/formcraft/file-upload/server/content/files/16080a63b5e92a---18169461146.pdfIn PDF document text
    • https://www.eziblank.com/wp-content/plugins/super-forms/uploads/php/files/5mtuvdej3rj2jou94koob2nvs4/roridotuwujini.pdfIn PDF document text
    • https://tehnol.ru/wp-content/plugins/formcraft/file-upload/server/content/files/16084a1d2f0d9c---zumedepi.pdfIn PDF document text
    • https://ipcare.nl/wp-content/plugins/super-forms/uploads/php/files/2d737rcakm9a1318j05jtbu4vb/sexox.pdfIn PDF document text
    • https://limpjet.com.br/wp-content/plugins/super-forms/uploads/php/files/0325bb02b36f35aa709d4b3a457ead33/31971917289.pdfIn PDF document text
    • https://accesoriosalmayor.com/images/userfiles/file/16128574648.pdfIn PDF document text
    • https://prsnashville.com/wp-content/plugins/super-forms/uploads/php/files/63681486913c9c576737f4ade0650eea/tuxulinuwenojenowufotup.pdfIn PDF document text
    • https://kalatranslation.co.uk/wp-content/plugins/super-forms/uploads/php/files/hcig4udad9f7ao3468sgrcqbio/diregisikij.pdfIn PDF document text
    • https://www.costaverde.it/wp-content/plugins/formcraft/file-upload/server/content/files/1608c827786608---81661226898.pdfIn PDF document text
    • https://goactive.hu/wp-content/plugins/super-forms/uploads/php/files/ca790344eba5b5cae7b31dceb9ab6f25/wewebonurusoz.pdfIn PDF document text
    • https://www.medipratik.com/wp-content/plugins/formcraft/file-upload/server/content/files/16078a200df7a8---gixuduzalamarasixoti.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/Uplcv/~3/3vuEKuznOb8/uplcv?utm_term=tax+rate+on+reportable+employer+superannuation+contributionsPDF 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_off0000cdff.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCDFF 5340 bytes
SHA-256: 198ee02d0b4fd0a78dae0935ad45d4cbc3611f7397fedd177dcf2436770ba906
font_01_sfnt_off0000e01b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE01B 9972 bytes
SHA-256: 0ac6bf95ced8f043b02a520ff8b736a1463017f50bd13fdaa3a80079bb26d2f0