Malicious PDF — malware analysis report

Static analysis result for SHA-256 71b5f0da2bc99c68…

MALICIOUS

PDF

85.2 KB Created: 2021-09-17 00:45:42 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: b1826671c2fbd62592c5f6bd5938173c SHA-1: aea54c89e1ab551660088e25b9583d4896f6ad9f SHA-256: 71b5f0da2bc99c6812f03c150bd4316d3447a7b6b1fa530056cfc44514f6d3ae
126 Risk Score

Malware Insights

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

The PDF file was flagged by ClamAV and an ML classifier as malicious, with multiple heuristics indicating it functions as a link farm on disposable hosting. The embedded URLs likely lead to phishing sites or further malware downloads. The document body is heavily obfuscated, preventing a clear understanding of its specific lure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://synerhu.ru/uplcv?utm_term=google+voice+text+app+android PDF link annotation
    • http://envigest.cz/upload/file/22058901227.pdfIn PDF document text
    • http://veiligheidsslot.nl/ckfinder/userfiles/files/wejebomulo.pdfIn PDF document text
    • https://nacionalequipamentos.com/ckeditor/uploads/files/19790768043.pdfIn PDF document text
    • http://liebherr-tr.com/userfiles/file/ruxokuto.pdfIn PDF document text
    • http://pietrek.com/MARCUS/files/file/kabujapupobubamobavi.pdfIn PDF document text
    • https://www.goldenplanet.dk/wp-content/plugins/formcraft/file-upload/server/content/files/1612f5b0186f22---sudadifinagudekavufev.pdfIn PDF document text
    • http://studiozammuner.eu/userfiles/files/suwoxokodepizud.pdfIn PDF document text
    • http://chulatutoracademy.com/chulatutor/ckfinder/userfiles/files/99019562835.pdfIn PDF document text
    • http://bjerkelunden.org/content/files/userfiles/file///96473193135.pdfIn PDF document text
    • https://dwitunggaljaya.com/sitefiles/file/kijozenake.pdfIn PDF document text
    • http://rezidencianestor.sk/app/webroot/files/ckeditor/files/37119739760.pdfIn PDF document text
    • http://korea-labels.com/ckfinder/userfiles/files/rawojavepeni.pdfIn PDF document text
    • http://hotdeals24x7.com/ci/userfiles/files/44868579939.pdfIn PDF document text
    • http://camel-republic.com/media/userfiles/files/romusuxupabogefadu.pdfIn PDF document text
    • http://haihengpharm.com/upload/files/11006008622.pdfIn PDF document text
    • https://abbma.in/admin/uploads/file/jinutavagabudujisaxevar.pdfIn PDF document text
    • http://biurod9.pl/public/userfiles/file/10537653056.pdfIn PDF document text
    • http://officinedesign.it/userfiles/files/rijak.pdfIn PDF document text
    • http://dubilex.com/userfiles/files/98908427510.pdfIn PDF document text
    • https://renewone.de/files/4667807460.pdfIn PDF document text
    • http://abwjefferson.com/uploads/files/buxujatidijowojutomuj.pdfIn PDF document text
    • http://argyleliquidations.com/userfiles/files/9239339405.pdfIn PDF document text
    • http://nacyc.jp/Upload/file/wosidobigofa.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_off0000e867.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE867 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0001007e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1007E 10728 bytes
SHA-256: 715b8d2f5f0d6f762cc09dd27be5b9c04705a2048968917bab53167b74276d95
font_02_sfnt_off0001191e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1191E 17640 bytes
SHA-256: 9690c227d123e8a7c269698ff8bf0938c506d6bd9c586134aafa91975a58fe61

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