Malicious PDF — malware analysis report

Static analysis result for SHA-256 fc12d2c59bfcec0a…

MALICIOUS

PDF

74.9 KB Created: 2021-09-06 15:58:05 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: c5be81589e348c934bf139c15bde122d SHA-1: 8f403a7c64a64ba3e3c62901c8df1bdf4f1e5414 SHA-256: fc12d2c59bfcec0a1bc07e50626190869e264722e17b8195c50ca3e474279f60
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. Heuristics indicate it functions as a link farm, with many embedded URLs pointing to potentially compromised or disposable hosting. The document body is heavily obfuscated, preventing analysis of its specific content, but the overall structure and heuristic firings strongly suggest a phishing or malware distribution attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9990

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://bielwod.com/userfiles/file/pojizesaviwigixebivifo.pdf In PDF document text
    • http://toshiba-center.ru/uploads/files/67854832705.pdfIn PDF document text
    • https://popcouncilinstitute.org/wp-content/plugins/super-forms/uploads/php/files/e0817d9601478d088bc9d1244e3fc634/56960731961.pdfIn PDF document text
    • http://hkxhjfc.ltd/uploads/files/20210710115001.pdfIn PDF document text
    • https://stef-nancy.fr/upload/document/26900620288.pdfIn PDF document text
    • http://zdrowejaja.com/Upload/file/85849718087.pdfIn PDF document text
    • http://cohn-vossen.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606cc79e0cccb---sobojafazaxirefapunuxeb.pdfIn PDF document text
    • https://smoothnomad.com/wp-content/plugins/super-forms/uploads/php/files/5k7gjuanojfoopuu1kvlcdvf0g/87469630376.pdfIn PDF document text
    • http://brainerdhs71.com/clients/0/08/084bd9d902c6a1e3ee48703551c87841/File/gusogaxebo.pdfIn PDF document text
    • https://traveltokiev.com/wp-content/plugins/super-forms/uploads/php/files/prinajcnepp3s01g7bf8bv6bn1/96007492698.pdfIn PDF document text
    • http://matstravel.ru/userfiles/file/tinufurozobez.pdfIn PDF document text
    • http://www.carolglassman.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a3bd50380e5---gaximuviduvorogosazejor.pdfIn PDF document text
    • http://www.melodypods.com/wp-content/plugins/formcraft/file-upload/server/content/files/16129452fa99ff---94064001955.pdfIn PDF document text
    • https://luyenthitoeic.info/userfiles/file/rubomenogefevor.pdfIn PDF document text
    • http://wasserentkalkung.at/ckfinder/userfiles/files/nogopotiloxoxojewoteg.pdfIn PDF document text
    • http://sushistoryus.com/uploads/files/4459987334.pdfIn PDF document text
    • http://www.pattyn360.com/upload/forum/files/kalopikeme.pdfIn PDF document text
    • http://pro-elec.ru/ckfinder/userfiles/files/zopitij.pdfIn PDF document text
    • http://dodici12.ru/wp-content/plugins/super-forms/uploads/php/files/cfculusrnvsqcce648hmmbu710/maleruwukex.pdfIn PDF document text
    • http://suportti.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608032be82f9a---nuvuwedamopaxuto.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/6naE_Nh8_CY/uplcv?utm_term=uninformed+search+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_off0000c2ac.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC2AC 10748 bytes
SHA-256: 2c53977bc55cfb9f30e0ee70f961af38810bbc4bdfcfb518d43ff5c66131df77
font_01_sfnt_off0000db22.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDB22 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000f334.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF334 16836 bytes
SHA-256: b073641221ef8b9fbb7f3b5ac87fc059c5ca8e47a2884f6ef9bf94e2a5e53b09