Malicious PDF — malware analysis report

Static analysis result for SHA-256 a8c9ac208a153080…

MALICIOUS

PDF

81.2 KB Created: 2021-09-06 17:36:53 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 1f1c1f033927280aea25a192f43290d3 SHA-1: 1d412cb158280bd4062b17041ca1069660755502 SHA-256: a8c9ac208a15308036653da679a48bc50fcc7533b9fea78822128258cca18da0
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF document contains a large number of links, many of which point to compromised WordPress installations. The ML classifier and ClamAV detection strongly indicate malicious intent, classifying it as a phishing or trojan delivery mechanism. The presence of a link farm on disposable hosting further supports this, suggesting an attempt to distribute malicious content or phish users.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

Heuristics 7

  • 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.
  • Urgency / deadline lure low SE_URGENCY_LURE
    Document contains urgency or deadline language ('account will be terminated', 'action required within 24 hours', etc.) — useful context, but low-signal without other findings
  • 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://rrvchefs.com/wp-content/plugins/super-forms/uploads/php/files/0647981821da0871fa320ce2dd13ec61/40810156620.pdf In PDF document text
    • https://dentinale.eu/wp-content/plugins/super-forms/uploads/php/files/702a04dbc7d83bee61eb720a605286d4/32659572122.pdfIn PDF document text
    • http://signexpowholesale.com/project-new/christianbook/upload_images/file/gazixuwanuke.pdfIn PDF document text
    • http://rowanfamilyreunion.com/clients/28915/File/solepizidukaleti.pdfIn PDF document text
    • http://strojsteel.cz/webpagebuilder/ckfinder/userfiles/files/woxoratukoluwevufiven.pdfIn PDF document text
    • https://www.histoiresdegroupes.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609a4c422365e---savike.pdfIn PDF document text
    • http://nakatka.com/files/file/78034650163.pdfIn PDF document text
    • http://www.bewegeninarnhem.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1607398643a4b9---wejemojof.pdfIn PDF document text
    • https://censcakmu.org/board/file/files/silikugesixelosiz.pdfIn PDF document text
    • http://lhsclassof68.com/clients/73441/File/396946838.pdfIn PDF document text
    • http://asesorialuishervas.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609ef7741989e---mipowotuxufu.pdfIn PDF document text
    • https://lea-inc.com/wp-content/plugins/super-forms/uploads/php/files/28ae61d371fa01a4ae9ef1b02abe9b58/murukudejamipog.pdfIn PDF document text
    • https://miet.hu/kepek/vigesojamotonozax.pdfIn PDF document text
    • https://aartipalette.com/userfiles/file/14050886477.pdfIn PDF document text
    • https://genesisbehaviorcenter.com/wp-content/plugins/super-forms/uploads/php/files/c0a6f68ddae49012fb3e24853c1d10b9/kowopozad.pdfIn PDF document text
    • https://giriconsultancy.com/content_files/files/60301692714.pdfIn PDF document text
    • http://www.nbc.com.vn/ckfinder/userfiles/files/76305487185.pdfIn PDF document text
    • https://anzmrrn.org/wp-content/plugins/formcraft/file-upload/server/content/files/160afbf376b108---62268574641.pdfIn PDF document text
    • https://australiancaravancentre.com.au/application/third_party/ckfinder/userfiles/files/kupomewukasutaxov.pdfIn PDF document text
    • http://thefutureofgolf.eu/wp-content/plugins/formcraft/file-upload/server/content/files/1608b6da13009a---jibejejavafarekirufi.pdfIn PDF document text
    • http://odpadykj.cz/UserFiles/File/vuredunaxobajivijo.pdfIn PDF document text
    • http://flemingdecal.com/uploads/assets/file/64081794648.pdfIn PDF document text
    • http://xn--q20b13r9leepaeb.net/upload/file/202109030351346130.pdfIn PDF document text
    • http://murzilka.biz/images/uploads/file/zatevepuweja.pdfIn PDF document text
    • http://beiwendq.com//data/attachment/file/pefitavebe.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/3CAf4wW3hvY/uplcv?utm_term=sonnet+130+questions+and+answers+pdfPDF 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_off0000d734.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD734 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000ef46.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEF46 17412 bytes
SHA-256: 2d5c05a7a8399599ecaedf5d748bb825a8fe8bc4a6e85434c1a9318f928c9de1
font_02_sfnt_off00011c8d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11C8D 11200 bytes
SHA-256: b3693a3dfe56db5292821c46ec475d90a25659ca68cb18276b582ae4f70feb33