Malicious PDF — malware analysis report

Static analysis result for SHA-256 ef173a573682a5b8…

MALICIOUS

PDF

69.5 KB Created: 2021-09-28 13:58:55 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: e7275d61ec69526df2ef9f64a5613596 SHA-1: 2c5eedc47010a23b8c6225f7a6c6fa383fc8b7c1 SHA-256: ef173a573682a5b85980acb11dc25357beb52aa8aa5626d4738e2e9c1bdc41cb
156 Risk Score

Malware Insights

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

The PDF file contains numerous embedded URLs, many of which point to potentially compromised websites or disposable hosting. Heuristics indicate this is a link farm, with a high ML score and ClamAV detection confirming malicious intent. The primary goal appears to be redirecting users to other malicious documents, likely as part of a phishing or malware distribution campaign.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9982

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://patroha.hu/file/kematugobegasoxe.pdf
    • http://aerotherminsulation.com/userfiles/file/wekemiwisidugiririwewuna.pdf
    • https://costarica4d.com/contents/files/93902330345.pdf
    • http://mobil-tech.com/files/lobegefafifeziwosivo.pdf
    • http://constructionone.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1614ce6da62e5a---88512243853.pdf
    • https://cryptobasics.biz/uploads/files/39757589914.pdf
    • http://ltpbetel.ro/userfiles/file/zarekimigefoxipebok.pdf
    • http://daglichtfilters.nl/ckfinder/userfiles/files/85996432366.pdf
    • http://www.iycadana.org/wp-content/plugins/super-forms/uploads/php/files/picm6o8r88avrvrcpmq5tg5e51/bojosolug.pdf
    • http://vividconcept.in/userfiles/file/foxufadamob.pdf
    • https://www.yoursurveysurveyors.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/16145745d84ba1---miwijinenulasot.pdf
    • http://unitekinfostructures.com/userfiles/file/96640640196.pdf
    • http://esoftland.com/userfiles/file/99125598967.pdf
    • https://hotlinepro.in/admin/userfiles/file/77954685909.pdf
    • http://miet-boot.ch/images/uploadedimages/file/zegemodovoliwizoziwawax.pdf
    • http://net-marketing.hu/images/files/rexurilure.pdf
    • http://zeci.nl/im/image/19330436610.pdf
    • http://invismortgagebroker.com/images/file/lawoneniwaxipu.pdf
    • http://tourhong.com/FileData/ckfinder/files/20210901_A12F8693CB4E2FCC.pdf
    • http://www.thunderesp.com/ckfinder/ckfinder.htmlfiles/zipemagikijitazo.pdf
    • https://drproperty.in/userfiles/file/1097390265.pdf
    • http://media-production.net/admin/ckfinder/userfiles/files/botimajijorof.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/DOqCt-cVA4I/uplcv?utm_term=games+for+windows+7+ultimate+32+bit
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000b09c.bin
985367ab13fae04357d4871945d6c6d64ddabbb0d325d8c566c8608b7b9d3787
pdf-font-stream PDF embedded font (sfnt) at offset 0xB09C 14712 bytes
font_01_sfnt_off0000d5c6.bin
9bb00ec0aa255a9a35f185f1bd63a5b2c5eb2844f70d86c974056f7dcbda0530
pdf-font-stream PDF embedded font (sfnt) at offset 0xD5C6 11220 bytes
font_02_sfnt_off0000f045.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xF045 16792 bytes