Malicious PDF — malware analysis report

Static analysis result for SHA-256 87848aa765d22303…

MALICIOUS

PDF

60.3 KB Created: 2021-06-20 14:45:47 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-12
MD5: b22361594734b47379ce8e8e385c2365 SHA-1: e7f62052e31feea4464f71473a4b4be48a4b9fe3 SHA-256: 87848aa765d223033a53a0bd5e8c7c5e6b983ed77c3e9dcf36ec5c0ff95f95f7
156 Risk Score

Malware Insights

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

The PDF file was flagged by a machine learning classifier and ClamAV as malicious, indicating a high likelihood of malicious intent. It contains numerous links to external websites, many of which are hosted on compromised CMS platforms or disposable hosting, suggesting a link farm or phishing lure. The presence of PDF_SEO_DISPOSABLE_LINK_FARM and PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM heuristics further supports this, indicating the document is designed to direct users to potentially harmful sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

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://mariopresto.pl/userfiles/file/vudijiv.pdf In PDF document text
    • https://holzhaus-suedtirol.it/wp-content/plugins/formcraft/file-upload/server/content/files/1606f3d5654f0b---82517791718.pdfIn PDF document text
    • http://bestbelly.org/content/files/files/54173472250.pdfIn PDF document text
    • http://www.lifestaralberta.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609134162b433---94603793707.pdfIn PDF document text
    • http://www.bash.cl/media/file/zuwifolanakob.pdfIn PDF document text
    • http://themultifold.com/wp-content/plugins/super-forms/uploads/php/files/hqm4igkfpshvr7sd4kv3k36j37/bemilemusenovazevobixetof.pdfIn PDF document text
    • https://www.pietri-automobiles.com/wp-content/plugins/super-forms/uploads/php/files/nojnfqspfg1120bl6u6ddhcgv0/soboregusibaxiz.pdfIn PDF document text
    • http://caacoding.net/wp-content/plugins/formcraft/file-upload/server/content/files/160b070ed64346---43378429485.pdfIn PDF document text
    • http://mas.vacations/wp-content/plugins/formcraft/file-upload/server/content/files/160765b26c9acc---walejozumuga.pdfIn PDF document text
    • http://bet-balance.com/userfiles/file/91854708700.pdfIn PDF document text
    • http://adaviestransportltd.com/userfiles/file/12462596823.pdfIn PDF document text
    • https://thehamptonsbloomington.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608ae11e3bfd8---kudabojibuwepipuxipeg.pdfIn PDF document text
    • https://himalayanthailand.com/image/upload/File/nulubowebi.pdfIn PDF document text
    • https://www.varisistanbul.com/wp-content/plugins/formcraft/file-upload/server/content/files/160765ffd5cf4b---libujipovelupurutobep.pdfIn PDF document text
    • https://dienlanhbachkhoa.info/upload/files/telezexosuraxuwid.pdfIn PDF document text
    • http://ednak.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609d1a02ec7da---34365112544.pdfIn PDF document text
    • http://optimus.org.au/wp-content/plugins/formcraft/file-upload/server/content/files/1609a24b665291---11459803273.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/S30rS-6n6vg/uplcv?utm_term=four+deluxe+tracklistPDF 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_off0000af7a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xAF7A 5020 bytes
SHA-256: 94b3be13faeb25e52249cd91f5bb2b5d76d6d009f56bc0d70f17a228f3b08eb8
font_01_sfnt_off0000c09f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC09F 10280 bytes
SHA-256: 5d2c2a41e3999a8cbc512ff88a76d0a245ed15ae3f4c75ff10124ed8585d0d09