Malicious PDF — malware analysis report

Static analysis result for SHA-256 fb8768b378a15fb1…

MALICIOUS

PDF

88.8 KB Created: 2021-07-26 21:48:39 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-08-25
MD5: 13692cb776177a458bb23b5ffd2987a2 SHA-1: 0ef0d2e4ebf85a6a3b5686d3d1c8bacb54d40046 SHA-256: fb8768b378a15fb1506582eb5ba36b4066c57a80c15c7d2a6158f6e8d1f73c20
156 Risk Score

Malware Insights

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

The PDF was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. It contains a large number of links, many of which point to compromised WordPress sites, indicating a link farm designed to lure users to malicious content. The document body is heavily obfuscated and unreadable, suggesting an attempt to hide its true purpose.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9991

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://ednak.com/wp-content/plugins/formcraft/file-upload/server/content/files/16096e4e0a3f14---81404470846.pdf In PDF document text
    • https://audit-advisers.com/userfiles/file/99524300590.pdfIn PDF document text
    • https://www.baileysmilk.com/wp-content/plugins/super-forms/uploads/php/files/d6ec1631d99e8673994ecb2df63a0d0f/42974281921.pdfIn PDF document text
    • https://abugfreemind.com/userfiles/file/dimenozobapokotus.pdfIn PDF document text
    • http://www.kissdocs.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/16072eeda4f12b---jiwipebetabalexul.pdfIn PDF document text
    • https://honkakuji.jp/honkakuji/images/ckfinder/files/4602852334.pdfIn PDF document text
    • http://www.reroofingbrisbaneqld.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/160d1d5d7c2f90---59575076526.pdfIn PDF document text
    • http://nomaquito-travel.com/editor-images/53204673384.pdfIn PDF document text
    • http://www.mtpartnersfl.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a3fe36a3082---tumovirojitenunemosopin.pdfIn PDF document text
    • http://www.barankayalar.com.tr/wp-content/plugins/formcraft/file-upload/server/content/files/16070dd7b4aa88---juliz.pdfIn PDF document text
    • https://europartner2.pl/uploads/gugefejevupamelof.pdfIn PDF document text
    • http://dwhs79.com/clients/15834/File/gabupirasekixigogajuvex.pdfIn PDF document text
    • http://giga.sk/storage/file/xadetigavo.pdfIn PDF document text
    • http://raduzhniy.com/wp-content/plugins/formcraft/file-upload/server/content/files/16084a0de43d89---8037593322.pdfIn PDF document text
    • http://robinsonsmithreunion.com/clients/879094/File/xajepokena.pdfIn PDF document text
    • https://roweryelectra.eu/app/webroot/uploads/file/16199482471126.pdfIn PDF document text
    • https://alakharia.com/public_html/userfiles/file/gadeveziribeforu.pdfIn PDF document text
    • http://nnk.gr/wp-content/plugins/formcraft/file-upload/server/content/files/1609bb146227e7---34868140604.pdfIn PDF document text
    • http://glina-master.ru/admin/ckfinder/userfiles/files/kasudisikakenagase.pdfIn PDF document text
    • http://bonfiremadigan.com/uploads/fckeditor/file/saluroduniwokopo.pdfIn PDF document text
    • http://lordbeaverbrook1973.com/clients/76835/File/tiridikure.pdfIn PDF document text
    • https://wamsconference.com/wp-content/plugins/super-forms/uploads/php/files/c4bca395828c2f55a6b04436af1d4e24/gepevuwukibow.pdfIn PDF document text
    • http://www.holderit.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608d590e35fd4---72812471319.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/ngfLrbzwjls/uplcv?utm_term=nahan+ernani+cuenco+sheet+music+pdfPDF link annotation
    • https://schema.org/InStockIn PDF document text
    • 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_off0000f335.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF335 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00010b47.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10B47 18352 bytes
SHA-256: 12dcb05a7e27d612a1c1ecc40dfceaeb3c527ba918da143abe52c22a196b1094
font_02_sfnt_off00013c3e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13C3E 10916 bytes
SHA-256: 9d1b6e010a0890c5ae5dbc085bcb93f9d191370b49736fa644c8cd14f1b41ef2