Malicious PDF — malware analysis report

Static analysis result for SHA-256 331b904e47c56c34…

MALICIOUS

PDF

87.1 KB Created: 2021-09-22 10:01:59 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: 2952556028518db30fe1a049fe83e42b SHA-1: 66eba7322e63da7fcd523983a00f1a8f506c8933 SHA-256: 331b904e47c56c34f6827d09c0544bf458c970a4fa1df05b303ef1e45c044fac
156 Risk Score

Malware Insights

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

This PDF file was identified as malicious by ML classifiers and ClamAV, indicating a phishing or trojan threat. It functions as a link farm, with many embedded URLs pointing to potentially compromised websites, including those using CMS upload storage. The primary goal appears to be directing users to external, untrusted resources.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9942

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://anquocrealty.com/uploads/image/files/69283787940.pdf In PDF document text
    • http://www.kroonzuivel.nl/ckfinder/userfiles/files/77488780530.pdfIn PDF document text
    • https://chezgregoire.fr/userfiles/23544875771.pdfIn PDF document text
    • https://www.penyembuhanholistikreiki.com/wp-content/plugins/formcraft/file-upload/server/content/files/16133b199a7ca0---67235209159.pdfIn PDF document text
    • http://toyteepee.com/uploadfiles/file/210913235243774968lf3tge.pdfIn PDF document text
    • https://www.ikedatosou.com/wp-content/plugins/formcraft/file-upload/server/content/files/161336c24b3f94---rewulonuxufegamifogo.pdfIn PDF document text
    • https://mosallaesf.ir/uploads/ck/files/waxinudupa.pdfIn PDF document text
    • https://happy-playground.gr/uploads/_uploads/files/kugupimivepagunu.pdfIn PDF document text
    • http://www.fuchingrading.com/upload/file/71464811675.pdfIn PDF document text
    • https://eastmangroup.org/ckfinder/userfiles/files/piwevozenefozevevodito.pdfIn PDF document text
    • http://www.tecnobor.com/ckfinder/userfiles/files/sirisetofuxijafupuxigarob.pdfIn PDF document text
    • http://www.greddy.com/admin/common/ckfinder/userfiles/File/pewifedamize.pdfIn PDF document text
    • http://koutingchina.com/upload/files/90874626455.pdfIn PDF document text
    • http://recit-de-vie.fr/userfiles/file/3709889472.pdfIn PDF document text
    • http://maekuangudomthara.com/ckfinder/userfiles/files/dawapisanalojaba.pdfIn PDF document text
    • https://holcom-solar.com/webroot/img/files/wopogiwupunegizi.pdfIn PDF document text
    • http://markjfox.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/66345164745.pdfIn PDF document text
    • https://panoramabyty.cz/content/filezawomazas.pdfIn PDF document text
    • https://holzhaus-suedtirol.it/wp-content/plugins/formcraft/file-upload/server/content/files/16133eb9657a90---7631346499.pdfIn PDF document text
    • http://tanphatinst.com/vietkiendo/upload/file/tazebafoxonagujowetu.pdfIn PDF document text
    • http://fred-robin.com/ckfinder/userfiles/files/nonabosibarorefajuxabu.pdfIn PDF document text
    • http://thuannam.com/image/files/96683414619.pdfIn PDF document text
    • http://pitchdecor-construction.com/user_img/files/56125903007.pdfIn PDF document text
    • http://dichvumucin.com/upload/ckupload/files/2635856032.pdfIn PDF document text
    • http://leton.pl/userfiles/file/rejepasuburaxebuzagel.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/3CAf4wW3hvY/uplcv?utm_term=best+calorie+tracker+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_off0000ee0f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEE0F 10508 bytes
SHA-256: 982c9b95d23ffc20f29391838fdfa9571dc9bd3032d1a30bb4ce4ff46e590b06
font_01_sfnt_off0001061c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1061C 18552 bytes
SHA-256: 290a31cd3fe568207efdefbdcbb2500f664fc2099d8de4996c4c13e9b447d990
font_02_sfnt_off000136ca.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x136CA 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1