Malicious PDF — malware analysis report

Static analysis result for SHA-256 7f659a760da47799…

MALICIOUS

PDF

79.4 KB Created: 2021-09-22 10:47:10 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-02
MD5: 150809ea1e8214c8b62466dcaebc2da9 SHA-1: 4ea82585ad9638b56ba5379a2d4ef97a6ef06637 SHA-256: 7f659a760da47799ceffee96f530a1ec9ec32c98e52d26ce0123e1c2602d4d7c
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains a link farm with 30 distinct links pointing to various domains, many of which are hosted on compromised CMS upload storage or disposable hosting. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or malware distribution. While no scripts were directly extracted, the embedded URLs and the nature of the link farm suggest an attempt to redirect users to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9981

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://thinhhoanggia.vn/Images_upload/files/30173274905.pdf In PDF document text
    • https://aptitudeclass.com/ckfinder/userfiles/files/15025804996.pdfIn PDF document text
    • http://scsytech.com/upload/files/xijudowedijiwawadenekoxom.pdfIn PDF document text
    • https://hattoco.vn/images/ckeditor/files/25746944493.pdfIn PDF document text
    • https://diphong.com/uploads/86395686388.pdfIn PDF document text
    • http://epmresearch.org/userfiles/files/36569710171.pdfIn PDF document text
    • http://ig-einheitsloks.de/medien/file/44696803447.pdfIn PDF document text
    • https://movie2book.com/userfiles/file/5629382216.pdfIn PDF document text
    • https://jancsoalapitvany.hu/ckfinder/userfiles/files/dasanude.pdfIn PDF document text
    • http://knshzj.com/CKEdit/upload/files/muxibatabosivuw.pdfIn PDF document text
    • http://niktid.ru/userfiles/file/zemetalaleka.pdfIn PDF document text
    • http://www.shipsupply.co.mz/wp-content/plugins/formcraft/file-upload/server/content/files/16133b75f9a215---81840966348.pdfIn PDF document text
    • http://xn--b1afklwjc5g.xn--p1ai/ckfinder/userfiles/files/48911335016.pdfIn PDF document text
    • http://keitbg.com/images/files/40100725745.pdfIn PDF document text
    • https://ceccarmaramures.ro/userfiles/file/14537312996.pdfIn PDF document text
    • https://www.abrasco.org.br/ckfinder/userfiles/files/46361210189.pdfIn PDF document text
    • https://bodykneadstherapy.com.au/ckfinder/userfiles/files/36662960620.pdfIn PDF document text
    • http://lisahyatthealth.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612f3bfd603b5---gurobabugafovu.pdfIn PDF document text
    • http://fine-trading-knotwork.com/uploads/media/80221479019.pdfIn PDF document text
    • http://winteringlawoffice.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/65952427436.pdfIn PDF document text
    • http://hoangnamjsc.com/upload/files/pidegapuwo.pdfIn PDF document text
    • https://rebates.forex/wp-content/plugins/super-forms/uploads/php/files/cc24nse8celm02llm2q8b18jr2/tomodixubolezabawexiz.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/3CAf4wW3hvY/uplcv?utm_term=indian+train+appPDF 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_off0000d140.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD140 18740 bytes
SHA-256: 7cc99f1591e924554476ff5445e382bc3a3151de7106e0f244e59a1a1f8ce82f
font_01_sfnt_off00010283.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10283 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00011a99.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11A99 9872 bytes
SHA-256: 1104d42f2e5f86863dd96ec1943dfe7f45fdd5488a3ec0856191f8b306f83adb