Malicious PDF — malware analysis report

Static analysis result for SHA-256 cd391158f74f9706…

MALICIOUS

PDF

82.9 KB Created: 2021-09-03 17:33:06 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: 8357576768f7e200eb286b1027fc47f3 SHA-1: d707d687619067ee076f6602a4b1e312e24a0445 SHA-256: cd391158f74f9706495be8d1da12100fcde3e71c4cc706ba106f5d6fd80c1e7a
156 Risk Score

Malware Insights

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

The PDF was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, pointing to numerous external URLs, some hosted on compromised CMS uploads. The document body is heavily obfuscated and appears to be metadata from the wkhtmltopdf tool rather than user-readable content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9917

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://nhachoxebus.com/upload/fck/file/16016665443.pdf In PDF document text
    • http://brainbond.ro/userfiles/file/15683108074.pdfIn PDF document text
    • https://luyenthitoeic.info/userfiles/file/kogimizuvivexonasepige.pdfIn PDF document text
    • http://montri-inspection.com/naichabub.co.th/images/upload/userfiles/files/tibazax.pdfIn PDF document text
    • https://wemservice.com/ckfinder/userfiles/files/mujawenenas.pdfIn PDF document text
    • https://diaspoassur.com/wp-content/plugins/super-forms/uploads/php/files/8d3f5c9333c5a78c07d9e2bd8bca6319/govupomivifubitefa.pdfIn PDF document text
    • http://namlongprojects.com/images/uploads/files/21002327911.pdfIn PDF document text
    • https://nhatngudongkinh.com/upload/ckupload/files/vivixaseseridow.pdfIn PDF document text
    • http://learnersdigest.org/userfiles/file/67231925408.pdfIn PDF document text
    • http://fittbikese.hu/files/file/67259177130.pdfIn PDF document text
    • http://dc-536514926e84.632.ch/ckfinder/userfiles/files/fomowuxumixegogumenuz.pdfIn PDF document text
    • https://chocoinmobiliario.com/wp-content/plugins/super-forms/uploads/php/files/4589948c709e70695b5486056010cb13/26230281221.pdfIn PDF document text
    • http://manavpublicschool.org/manav/userfiles/file/sumelubur.pdfIn PDF document text
    • https://socialchangefactory.org/wp-content/plugins/super-forms/uploads/php/files/fe6e4d25af3728dc840dbd5ad91c1674/75020327378.pdfIn PDF document text
    • https://nabijdefossa.nl/upload/files/torenujubaxar.pdfIn PDF document text
    • http://igigeothermal.jp/userfiles/file/wodimuximowagijerat.pdfIn PDF document text
    • http://terrietanaka.com/library/files/setanajezuzak.pdfIn PDF document text
    • http://hurtmar.pl/Upload/file/wonutage.pdfIn PDF document text
    • http://lube-stc.com/ckfinder/userfiles/files/84386289833.pdfIn PDF document text
    • https://grandegroup.net/files/59403390919.pdfIn PDF document text
    • https://gift-edu.ru/wp-content/plugins/super-forms/uploads/php/files/19e2cefc79068df8cf392fd3459040ec/89668140773.pdfIn PDF document text
    • http://omonetach.pl/foto/ilustracje/file/ligatukabafat.pdfIn PDF document text
    • http://www.orarestauratorisaf.it/wp-content/plugins/formcraft/file-upload/server/content/files/160b2f2746f428---62985989778.pdfIn PDF document text
    • http://freehajjandumrah.com/admin/admin/uploadfiles/file/vituxasigala.pdfIn PDF document text
    • https://jajugroup.com/ckfinder/userfiles/files/situxen.pdfIn PDF document text
    • http://recruiters-zone.com/wp-content/plugins/formcraft/file-upload/server/content/files/16082fe9f21845---40326586758.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/BkSY9tpko7c/uplcv?utm_term=positive+thinking+skills+pdfPDF 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_off0000e088.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE088 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f89f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF89F 10672 bytes
SHA-256: 9115cca4240ace77935c669b34b1557bba68089864f59975317868d3e40a713e
font_02_sfnt_off000110d6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x110D6 17560 bytes
SHA-256: a3d1676c057493371cb209601b0284b4743ab7d898c582e36aa564aa1d69b7ed

Open this report in the interactive analyzer, or submit your own file for analysis.