Malicious PDF — malware analysis report

Static analysis result for SHA-256 b66f0bd94941f288…

MALICIOUS

PDF

79.8 KB Created: 2021-10-08 13:52:00 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-20
MD5: a1391f6539b3138f8796b279506691e4 SHA-1: 2088a9840e2122e6bb50a37418b5487f4eaeed76 SHA-256: b66f0bd94941f2888c71b01347d2e6264dfcf28ab28b2c0c304d6402e89521b2
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF containing embedded JavaScript, which is a common technique for executing malicious code. It also features a link farm pointing to multiple external URLs, some of which are hosted on compromised CMS uploads, indicating a phishing or malware distribution attempt. The ML classifier and ClamAV detection strongly support its malicious nature.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9981

Heuristics 7

  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://garglob.ru/uplcv?utm_term=application+of+linear+algebra+in+electrical+circuits PDF link annotation
    • http://santinitravel.co/files/others/23033169207.pdfIn PDF document text
    • http://eamenfaraz.com/cache/fck_files/file/57785401882.pdfIn PDF document text
    • https://alzubidi.com/userfiles/files/24969984581.pdfIn PDF document text
    • http://herbwaterthailand.com/userfiles/files/boliwej.pdfIn PDF document text
    • https://alenakovalchuk.ru/wp-content/plugins/super-forms/uploads/php/files/21e6e8116e2ab11edefa47c672c366ff/34335936555.pdfIn PDF document text
    • http://vecsecity.info/editor_up/56573432414.pdfIn PDF document text
    • http://galettedesrois.hu/userfiles/file/tetok.pdfIn PDF document text
    • https://www.fibertech1.com/my_content/js/ckfinder/userfiles/files/jotajikudifelizotufili.pdfIn PDF document text
    • http://www.risingstars.com.tr/wp-content/plugins/formcraft/file-upload/server/content/files/16141983c29c4c---raxukosutaju.pdfIn PDF document text
    • http://www.oknookna.pl/wp-content/plugins/formcraft/file-upload/server/content/files/1613df4c9b490c---buzabanulalumit.pdfIn PDF document text
    • http://benetalent.com/upload/files/53068047110.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614e75db7a143---33962299354.pdfIn PDF document text
    • http://otevrel.eu/ckfinder/userfiles/files/fitujubefezeja.pdfIn PDF document text
    • http://www.satit.nrru.ac.th/satit/_Adminis/ckfinder/userfiles/files/reborizide.pdfIn PDF document text
    • http://kleinschaden-expert.de/userfiles/file/60516517994.pdfIn PDF document text
    • https://zivotzaokny.eu/res/file/tirade.pdfIn PDF document text
    • http://deauville.ru/files/file/xodasozukufurepa.pdfIn PDF document text
    • http://yangs-ns.com/ckfinder/userfiles/files/20210924022530.pdfIn PDF document text
    • https://pelicanfinancialnetwork.net/ckfinder/userfiles/files/25797940297.pdfIn PDF document text
    • https://listapp.in/ci/userfiles/files/pelamazabuwowemufa.pdfIn PDF document text
    • https://www.eos.org.eg/ckfinder/userfiles/files/junosaxofepafuwor.pdfIn PDF document text
    • http://ziva-muzika.cz/files/file/18584553998.pdfIn PDF document text
    • 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_off0000d12f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD12F 18532 bytes
SHA-256: 8a5e430b48653eaabbdffc8c1d9fc72ae7592682aa9447062bebe7157e1fb5de
font_01_sfnt_off0000ffd0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFFD0 10876 bytes
SHA-256: 10845d5e08d538290feb0273e258df21fd11de4063731d12a081036ba17065a0
font_02_sfnt_off000118ef.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x118EF 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1