Malicious PDF — malware analysis report

Static analysis result for SHA-256 8278d847e914b09c…

MALICIOUS

PDF

78.9 KB Created: 2021-09-08 14:53:36 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: a3b2da87fd5fc97f1e6b89b135ed0870 SHA-1: 3ac3b411643d9adfe6fdbf2c040e5f4b0c07adf3 SHA-256: 8278d847e914b09cf9bea7562ebf44526bd9a3faf31b6b15fd0c5008685a408a
172 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript and numerous external URIs, many of which are part of a link farm hosted on disposable or compromised domains. The ClamAV detection and ML classifier strongly indicate malicious intent, likely for phishing or malware distribution by presenting deceptive download links. The presence of embedded JavaScript suggests potential for further exploitation or payload delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9993

Heuristics 8

  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • Visual download / call-to-action button lure low SE_DOWNLOAD_BUTTON
    Document contains a call-to-action phrase ('Click here to download', 'Download Now', etc.) — low-signal unless other findings point to a malicious workflow
  • 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://cructi.ru/uplcv?utm_term=railway+alp+psychological+test+books+pdf
    • https://tsegypt.com/file/fituzibonufefurik.pdf
    • http://matchedtubes.de/userfiles/file/61940575061.pdf
    • http://phongkhamthienhoa.vn/images/files/54147618870.pdf
    • https://mertlakustika.cz/images/pages/file/baxukexifik.pdf
    • http://stylekd.ru/files/26324827293.pdf
    • https://stpetejazz.com/wp-content/plugins/super-forms/uploads/php/files/7d2rnarb6i7mmuhlc82fec7271/nuvowewosif.pdf
    • http://eschool365.in/js/admin/uploadfiles/file/vidixuxamisujojewodeve.pdf
    • http://for-rent-aalst.com/wp-content/plugins/formcraft/file-upload/server/content/files/161333b94e69ac---88611682950.pdf
    • http://weighlessthisyear.com/ckfinder/userfiles/files/85889725839.pdf
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/16131f9b329889---jopazewajowipozafa.pdf
    • http://rotarycochinharbour.org/ci/userfiles/files/simaxomar.pdf
    • https://osikovo.eu/webroot/img/content/files/23824436090.pdf
    • http://elitakhealing.com/ckfinder/userfiles/files/veguzevemim.pdf
    • https://hcs1000.org/wp-content/plugins/super-forms/uploads/php/files/9bc8c6445d1e7a6eee2e9199a5fcd069/dorafadipowil.pdf
    • http://onlinemidias.com/ckfinder/userfiles/files/52530142272.pdf
    • https://biserica-izvorul-tamaduirii.ro/files/42313313318.pdf
    • http://compow.net/ckfinder/userfiles/files/2579244213.pdf
    • http://grgct.com/ckfinder/userfiles/files/kutas.pdf
    • https://dagvandearchitectuur.be/_files/file/pabebemenunatudaxazofux.pdf
    • http://generale-bureautique.fr/gdb/files/file/5426709945.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_off0000c6e9.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xC6E9 16792 bytes
font_01_sfnt_off0000df00.bin
e7136a5bd134d648a279fc337ce75262375586a0c507fd1424c3e35900e87ac4
pdf-font-stream PDF embedded font (sfnt) at offset 0xDF00 11172 bytes
font_02_sfnt_off0000f8f2.bin
6014ac48ceff38826c866d67a4123d8b6e63153aed097e86f17fd23ff0543e88
pdf-font-stream PDF embedded font (sfnt) at offset 0xF8F2 20452 bytes