Malicious PDF — malware analysis report

Static analysis result for SHA-256 e37840cafaed47f6…

MALICIOUS

PDF

86.7 KB Created: 2021-06-25 21:58:15 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 2c81d750b1b77752585b987a9b5e0c29 SHA-1: f667bbf44719d60bdc9a108d14a44e51047bf84d SHA-256: e37840cafaed47f62afc6b81ce1cf3729a6e58166e32ae3dea9091b7b192e4bb
156 Risk Score

Malware Insights

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

The PDF file was flagged by multiple heuristics and a machine learning classifier as malicious, with ClamAV identifying it as a phishing trojan. It contains numerous links to external websites, many of which are hosted on compromised CMS uploads or disposable domains, suggesting a link farm designed to redirect users to malicious content. The document body is heavily obfuscated and appears to be generated by wkhtmltopdf, further obscuring its true intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9947

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://baschin-heizung.com/meineBilderAlbertGrundschule/file/74543587674.pdf
    • https://aprilboya.com/userfiles/file/saguduvagomola.pdf
    • https://www.sharpeningfactory.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a6d5ce96a4a---belagadaxevejasogif.pdf
    • http://arci-mp.fr/admin/File/daronimo.pdf
    • http://itkaufmann.com/images/fckimages/file/vemuxutawuk.pdf
    • https://goldenparadisestsimons.com/wp-content/plugins/super-forms/uploads/php/files/020b08e759847804677af89469176745/62218240842.pdf
    • https://ridersshop.it/file/golazig.pdf
    • https://khonggiansachhanoi.vn/uploads/files/91665953620.pdf
    • https://balance-global.com/wp-content/plugins/super-forms/uploads/php/files/56fhkaamfbplpfqksijirti0qh/54626588389.pdf
    • http://ligneus.hu/upload/file/66940562896.pdf
    • https://grafitpoint.ru/wp-content/plugins/super-forms/uploads/php/files/210fde15eb2f97d7e016b595eed19d4a/vunazurobosapimig.pdf
    • https://gk-termopanel.ru/wp-content/plugins/super-forms/uploads/php/files/652ebb53ff38a8da92a1a5b54abc8eb6/97167237832.pdf
    • https://luxartparquet.com/wp-content/plugins/super-forms/uploads/php/files/e0c040da7caaf78e167f81acb02e7a86/xugixetivologo.pdf
    • https://www.gs-gleichmann.de/wp-content/plugins/formcraft/file-upload/server/content/files/160ba67256dd7f---9110340307.pdf
    • http://nw-line.ru/generic/uploaded/surejotigi.pdf
    • https://www.duffylighting.com/wp-content/plugins/super-forms/uploads/php/files/79266ccc67444d91d7c48715b990e4b3/68573821046.pdf
    • http://www.expo-hotel.com/english/wp-content/plugins/formcraft/file-upload/server/content/files/160a7f98db4179---18207915912.pdf
    • https://sjalikave.hu/pictures/file/luzobab.pdf
    • https://www.web2business.pt/wp-content/plugins/formcraft/file-upload/server/content/files/1607db1afe6a7b---bitekep.pdf
    • https://trellisdundee.com/wp-content/plugins/super-forms/uploads/php/files/20f83cd9bf3abbbe68ce5366cec7efe6/90174812417.pdf
    • http://erfolgsapp.de/wp-content/plugins/formcraft/file-upload/server/content/files/16072499305e61---41284906053.pdf
    • http://webinaris.net/ckfinder/userfiles/publics/files/xatozinevex.pdf
    • http://paintingservicesonline.ca/wp-content/plugins/formcraft/file-upload/server/content/files/1606feef930008---72119191735.pdf
    • https://biothiennam.com/media/ftp/file/pejunitukutefavevomalal.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/fzgW7-mxBc0/uplcv?utm_term=tamra+real+housewives+of+orange+county
    • 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_off0000ef47.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xEF47 16792 bytes
font_01_sfnt_off0001075e.bin
7afadd9933fa6ffc21646313c023e4918b86b46aa5093f8a9569b3e3bab397d0
pdf-font-stream PDF embedded font (sfnt) at offset 0x1075E 11112 bytes
font_02_sfnt_off00012130.bin
d71625a982200ef5ed97e99921b7bc372ccddc256fb5982fbc0afe306814d0de
pdf-font-stream PDF embedded font (sfnt) at offset 0x12130 17036 bytes