Malicious PDF — malware analysis report

Static analysis result for SHA-256 41656000ce9b2b93…

MALICIOUS

PDF

85.9 KB Created: 2021-07-05 03:49:59 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 042273e026481735c5e420825d004968 SHA-1: 0fa53d2a39d5aa2d94c88f2be30babe8608bffa0 SHA-256: 41656000ce9b2b9320f960c7bd2444db667511e269afaf4dcb313db33d7164f7
156 Risk Score

Malware Insights

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

The PDF contains numerous links pointing to compromised WordPress sites and disposable hosting, indicating it functions as a link farm. The ClamAV detection and ML classifier strongly suggest malicious intent, likely for phishing or distributing further malware. The file's structure and numerous external links are consistent with a spearphishing attachment used to lure victims to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9952

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 https://inwebjor.ru/uplcv?utm_term=conference+proceedings+apa+7th
    • http://musorcentrum.hu/files/article/file/kadojafimelugek.pdf
    • https://ifacemount.com/wp-content/plugins/super-forms/uploads/php/files/s150fbb0uujnrldsnojo40rg7a/50139501985.pdf
    • http://etasystem.net/userfiles/files/motojujapixux.pdf
    • http://for-rent-antwerp.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b49752f1c6d---ragifezewipa.pdf
    • http://bmhs71.com/clients/c/c9/c97ff408e01126d63256cf68004d6641/File/jubevulufoganemufimib.pdf
    • https://www.3dreamchurch.com/wp-content/plugins/super-forms/uploads/php/files/2b0929e469cb3bb2e38a43fcfb7da0a0/30034823251.pdf
    • http://xn--939a66v0zjo3bcvdmrp.com/data/ckfinder/files/tibezowavolupov.pdf
    • http://www.auditsi.com/wp-content/plugins/formcraft/file-upload/server/content/files/160aec5a1833c5---topolowenilevakasoxaxiku.pdf
    • http://www.leesii.com/wp-content/plugins/formcraft/file-upload/server/content/files/160acc508ea4f4---zekogepeporos.pdf
    • http://udaybharat.in/ckfinder/userfiles/files/98891944993.pdf
    • http://www.commandinglife.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606c9f5b58d0d---rabazi.pdf
    • http://bilagroup.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c41fafc5f0f---90253541293.pdf
    • https://www.carlosfunes.es/wp-content/plugins/formcraft/file-upload/server/content/files/1607ccbbe5208d---21139279934.pdf
    • http://kimbuunguyen.com/uploads/userfiles/file/68554099421.pdf
    • http://automsystem.com/UploadFile/file/20210626215920848.pdf
    • http://www.majorisinvestimentos.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1608d0fcade424---xinegaputigejuzolewa.pdf
    • http://pc-driver.ru/userfiles/files/88864498653.pdf
    • https://www.phoenixdentalacademy.co.uk/wp-content/plugins/super-forms/uploads/php/files/e7a5a4392c5c8546ab3d5f8be8e032a8/13877051571.pdf
    • http://pincailight.com/zk/UploadFile/file/2021061817243173499.pdf
    • http://zamokugrofa.sk/admin/fckeditor/file/40269613715.pdf
    • https://www.peeryhotel.com/wp-content/plugins/super-forms/uploads/php/files/f1b7978607b82182cbc687ebe537d001/84551608781.pdf
    • https://popcouncilinstitute.org/wp-content/plugins/super-forms/uploads/php/files/8022cfebd2b6b3be0247f51b3988449a/72949579352.pdf
    • https://brianhigbielaw.com/UserFiles/file/fubizufopuxo.pdf
    • 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_off0000ebf1.bin
fefa2b7cb10dc47dd5cbcf129b82e1b5c340fa19bd65f4eb5c353adf58c1b5a9
pdf-font-stream PDF embedded font (sfnt) at offset 0xEBF1 10936 bytes
font_01_sfnt_off00010521.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x10521 16792 bytes
font_02_sfnt_off00011d33.bin
acb35a6ba98e5693713ff72aa1587022e07a657d17a494381c0e7db606f7c3c9
pdf-font-stream PDF embedded font (sfnt) at offset 0x11D33 17324 bytes