Malicious PDF — malware analysis report

Static analysis result for SHA-256 738d9a159b035720…

MALICIOUS

PDF

68.8 KB Created: 2021-09-11 06:10:02 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: 89bf8d7d3fd2a9ace54446a9dbf5b2d7 SHA-1: d49fde03c1dfe10650ac43097c09b1264b5a964c SHA-256: 738d9a159b035720381753f6382d2b951889bc5970fdc4cb071fdd509a577f89
156 Risk Score

Malware Insights

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

The PDF file was identified as malicious by ClamAV and an ML classifier. It contains numerous links, many of which point to external websites, including some hosted on compromised CMS upload directories. The document body is heavily obfuscated and appears to be generated by wkhtmltopdf, suggesting it's not intended for direct user reading but rather as a vehicle for hosting these links. The presence of link farms on disposable hosting and compromised CMS uploads indicates a likely attempt to distribute malicious content or phish users.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9982

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 http://iweldbot.com/ckfinder/pho/files/24892056842.pdf In PDF document text
    • https://nolimitscenter.be/peausitive/images/FCKeditor/file/12215197267.pdfIn PDF document text
    • http://rockpapersun.com/upload_mce_image/file/25421567929.pdfIn PDF document text
    • https://stvorki.ru/files/file/68786913835.pdfIn PDF document text
    • http://barbusci.it/maisUserFile/file/26538806464.pdfIn PDF document text
    • http://savitaco.com/uploads/images/files/pagunibepegavigegu.pdfIn PDF document text
    • https://morganmethod.tuesdaytrader.com/ci/userfiles/files/49110125951.pdfIn PDF document text
    • https://www.intermediastudios.com.mx/wp-content/plugins/super-forms/uploads/php/files/fae40ffd07eff69e1a729ea8ed92234d/kijijiwidew.pdfIn PDF document text
    • https://tessuno.com/upload/files/613b646e35ecc.pdfIn PDF document text
    • http://chinhlytailieuluutru.com/media/ftp/file/sipomukofak.pdfIn PDF document text
    • https://balajihighfields.in/userfiles/file/mirenegebugaxesujax.pdfIn PDF document text
    • https://southafricapools.com/contents/files/lumikeze.pdfIn PDF document text
    • http://hzqzg.com/d/files/fetutorusozizawilev.pdfIn PDF document text
    • https://commonlawhouse.in/userfiles/file/ladanuzozusarojirugosozi.pdfIn PDF document text
    • https://inchirierielicopter.ro/wp-content/plugins/formcraft/file-upload/server/content/files/161367687eb6e7---69285353502.pdfIn PDF document text
    • http://peknanevesta.sk/media/file/41164006471.pdfIn PDF document text
    • https://le27.fr/docs/file/71681605997.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/16132aa0af2b74---jupirolipozexuz.pdfIn PDF document text
    • http://aj-freight.com/ckfinder/userfiles/files/nuxixosajimukepowed.pdfIn PDF document text
    • https://www.xyoaa.org/sites/default/files/files/fizifasobopowopepaka.pdfIn PDF document text
    • http://laulumaja.fi/ckfinder/userfiles/files/61550301306.pdfIn PDF document text
    • http://shqinze.net/admin/upimg/file///81092204328.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/PmAiG5ZyT-k/uplcv?utm_term=rpg+maker+mv+to+androidPDF 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_off0000b0c8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB0C8 10724 bytes
SHA-256: f91c88524e6c7005f075fb95ed6288003b90638cc89aa1fa6f90f29d155a2611
font_01_sfnt_off0000c92e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC92E 14628 bytes
SHA-256: 95a47cba37cd4c46a66ed5c19befdfe0f4073dfc74f9f06c40d577aa3f1284b2
font_02_sfnt_off0000edd7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEDD7 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1