Malicious PDF — malware analysis report

Static analysis result for SHA-256 ac55a34adb414096…

MALICIOUS

PDF

87.0 KB Created: 2021-07-09 11:48:38 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-14
MD5: 0ac72134cf531a212825bd4c7d65d6ca SHA-1: 1723fc326ede7baf7dba53ad9f93054aed1935ce SHA-256: ac55a34adb4140967e53eb2626acac579fc24b89636ee1663e6ad717cc7bd89a
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. The heuristics reveal it functions as a link farm, directing users to numerous external URLs, some hosted on compromised CMS platforms. The embedded URLs and the overall structure suggest a phishing or malware distribution attempt, likely initiated via spearphishing.

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 https://synerhu.ru/uplcv?utm_term=fiction+book+review+sample+pdf PDF link annotation
    • http://carroll1975.com/clients/4/4e/4e2b018d07aaa5a30c3e4fca1c7a8df7/File/golakijivamepapezu.pdfIn PDF document text
    • https://www.lamuccacompany.com/wp-content/plugins/super-forms/uploads/php/files/4acf170f38cca4ec8d05946471564890/wefipin.pdfIn PDF document text
    • https://turismopontevedra.com/ckfinder/userfiles/files/pazujasinedefid.pdfIn PDF document text
    • https://studiogreenwich.ru/wp-content/plugins/super-forms/uploads/php/files/89d8823d1d09a95328e8c55221eb9db0/pegemuxako.pdfIn PDF document text
    • http://www.kindytennis.com/wp-content/plugins/formcraft/file-upload/server/content/files/16077153138656---nuzulozugejudimoxutedo.pdfIn PDF document text
    • https://limsurdua.com/contents//files/xibetim.pdfIn PDF document text
    • https://mikepromedia.com/wp-content/plugins/super-forms/uploads/php/files/uelttqph8l9sj2lfjduni3hnm7/90252214247.pdfIn PDF document text
    • https://nailseasupportgroup.com/wp-content/plugins/super-forms/uploads/php/files/dabba97caf2897b3b352acff6863e54c/88242686045.pdfIn PDF document text
    • http://waypl.pl/upload/File/pukodafezuwaset.pdfIn PDF document text
    • https://www.mclarenpress.com/wp-content/plugins/formcraft/file-upload/server/content/files/16097ff1671a28---bilukutumifuv.pdfIn PDF document text
    • http://vizesblokk.hu/files/file/95033167181.pdfIn PDF document text
    • http://aelma.com/sites/default/userfiles/file/31060111230.pdfIn PDF document text
    • http://vladjurnalist.ru/archive/file/70806789617.pdfIn PDF document text
    • https://directprocessors.com/wp-content/plugins/formcraft/file-upload/server/content/files/160d649c300643---40947402108.pdfIn PDF document text
    • https://standardpromotion.com/images/upload/userfiles/files/liramoneziximo.pdfIn PDF document text
    • https://thejasmineway.net/wp-content/plugins/super-forms/uploads/php/files/5v0r9h1s09sqav1c001t4pjsib/54116135779.pdfIn PDF document text
    • http://caribsplash.org/wp-content/plugins/formcraft/file-upload/server/content/files/160920b20d7534---34372721544.pdfIn PDF document text
    • https://www.alongsideasia.com/wp-content/plugins/super-forms/uploads/php/files/9e1df3ced14dc14f2919233320222bd7/19916599818.pdfIn PDF document text
    • http://armiikrajowej36.pl/public/upload/ckfinder//userfiles/files/79059701664.pdfIn PDF document text
    • https://www.pal-kont.hu/wp-content/plugins/super-forms/uploads/php/files/a766aa93bbf0386b70e36551de322ff8/patexuvojusegasuxeresoduk.pdfIn PDF document text
    • https://www.edutechusa.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609b691280cb0---tinedaxipiwivomipux.pdfIn PDF document text
    • https://atlasautoglass.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bc31e216345---bizutuduxurafefoxixi.pdfIn PDF document text
    • http://www.viksexteriors.com/wp-content/plugins/formcraft/file-upload/server/content/files/160789e359e484---16154296466.pdfIn PDF document text
    • https://bokseinstituttet.dk/wp-content/plugins/formcraft/file-upload/server/content/files/16079a0e65b4d2---75676053333.pdfIn PDF document text
    • https://www.beachesbrewing.com/wp-content/plugins/super-forms/uploads/php/files/6a208b2e6eeacac83e60c5913626dd63/96988320267.pdfIn 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_off0000ef7d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEF7D 11140 bytes
SHA-256: 8437e07e851b61102f7d4771514f21ee6c0ca002a83f994093eb8acbae8ac1d0
font_01_sfnt_off00010960.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10960 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00012172.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12172 17260 bytes
SHA-256: 9863c24ed2b0bc79d94832c6f2dcf1aaaf6dc070d7995330cfe7048d4f3c4c08