Malicious PDF — malware analysis report

Static analysis result for SHA-256 a4351c42d88e1a7d…

MALICIOUS

PDF

87.0 KB Created: 2021-09-17 08:43:41 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: b6fa9ed9c98a5f2fc0e033e3d4afdc7d SHA-1: 6d45d3cfcdb75dfe9db84689179839699599859b SHA-256: a4351c42d88e1a7db3f94e1798dad489054e7de946f8803f4f58d91b35cdbd8f
156 Risk Score

Malware Insights

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

The PDF contains a large number of embedded URLs, many of which point to disposable hosting or compromised CMS upload directories, indicative of a link farm. The ML classifier and ClamAV detection strongly suggest malicious intent, likely phishing or malware distribution. The primary attack pattern involves luring users to external sites via these links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9905

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://lighthousemacau.com/html_upload/file/sovedidimodugi.pdf In PDF document text
    • http://clubesquilacoma.com/uploads/files/perefet.pdfIn PDF document text
    • https://www.horisunmauritius.com/wp-content/plugins/super-forms/uploads/php/files/9eb839df475f5677fbcfdd1fa435ed2f/tupuwuvame.pdfIn PDF document text
    • http://naturalmis.com/userfiles/file/pipagagifavabisusaxisi.pdfIn PDF document text
    • http://pampa.be/uploads/userfiles/files/nojanajorivapepatagokimo.pdfIn PDF document text
    • http://dioceseofniranam.org/userfiles/file/vivebiji.pdfIn PDF document text
    • http://zbirozskepodzamci.cz/userfiles/sotasurefefigosevikesaju.pdfIn PDF document text
    • https://hightechrustremovers.nl/wp-content/plugins/formcraft/file-upload/server/content/files/16131d0f545fd2---somavorobimarelax.pdfIn PDF document text
    • http://stelmart.ru/userfiles/file/datomaw.pdfIn PDF document text
    • http://consulcongress.it/uploads/assets/file/dinorivesezolitadekitijen.pdfIn PDF document text
    • http://opusbiz.kr/data/editor/file/20963169656140753742546.pdfIn PDF document text
    • https://gazeta-msp.pl/user_files/File/20831761827.pdfIn PDF document text
    • http://fthyhs.com/resource/docContentImg/file/2021-09-16/a0019a578c456883b1f4fd6f73ccae27.pdfIn PDF document text
    • http://ulv-fogger.ru/d/files/59684485391.pdfIn PDF document text
    • http://www.theflightfest.com/wp-content/plugins/formcraft/file-upload/server/content/files/16142660cdc59f---matazit.pdfIn PDF document text
    • https://ppkh.net/userfiles/file/75495575188.pdfIn PDF document text
    • http://idealthailand.com/file_media/file_image/file/69451137189.pdfIn PDF document text
    • https://betamachinery.sa/other_files/File/besolezavoduvo.pdfIn PDF document text
    • https://quatcongnghieput.com/uploads/files/36596434863.pdfIn PDF document text
    • http://metamorfozyayincilik.com/userfiles/file/xizibimukaraxigi.pdfIn PDF document text
    • http://www.asiacoservice.com/file/files/77339261406.pdfIn PDF document text
    • http://www.civilhospitalpalampur.in/img/uploads/files/ronezepokefofi.pdfIn PDF document text
    • https://www.advids.co/wp-content/plugins/formcraft/file-upload/server/content/files/16134f4b8cb99d---gakugixit.pdfIn PDF document text
    • https://ptogel2.com/contents/files/25703298503.pdfIn PDF document text
    • http://ancheng-medical.com/uploadfile/files/tobunolexuxozepam.pdfIn PDF document text
    • http://lnv-cnc.com/userfiles/file/113506237.pdfIn PDF document text
    • http://compie.ru/wp-content/plugins/formcraft/file-upload/server/content/files/1613c29dd88e11---62737516521.pdfIn PDF document text
    • http://ayurveda-shiatsu-qigong-nice.com/upload/files/47242897166.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/fzgW7-mxBc0/uplcv?utm_term=flvto+android+appPDF 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_off0000f331.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF331 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00010b48.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10B48 10128 bytes
SHA-256: 94585f7777a39cc20a271ba7a6a98b14c4aa8651fb8118fcc8abecc16843ef74
font_02_sfnt_off000121ee.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x121EE 17180 bytes
SHA-256: d69c155f997d7260e7e71debad5bfaf2a4aab64a1e8739e191e2c59a385a1b44