Malicious PDF — malware analysis report

Static analysis result for SHA-256 d35c3ad917b01656…

MALICIOUS

PDF

112.3 KB Created: 2021-06-28 07:33:16 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: ff7135954b86b74c48128e5ec29d709e SHA-1: cec8c9cff4e54a3ea9dfa7b3977f983eee1120f9 SHA-256: d35c3ad917b016567a33d8899229e29b6402bd8a5a504d6378eb6b003ea0121c
156 Risk Score

Malware Insights

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

The PDF file was flagged by ClamAV as Pdf.Phishing.Trojan and a machine learning classifier indicated a high probability of maliciousness. It contains numerous links to external websites, many hosted on compromised CMS platforms 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, providing no direct user-facing text but containing embedded URLs.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9958

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 https://oniceh.ru/uplcv?utm_term=a+man+in+full+chapter+summary
    • http://verduciautodemolizioni.it/userfiles/file/benelovejej.pdf
    • http://www.deep2001.com/images/library/File/fofaj.pdf
    • http://aliceinformaticasrl.com/user/pages/tazevaka.pdf
    • http://mesotects.com/wp-content/plugins/formcraft/file-upload/server/content/files/160d8b7614953c---rebusizadadubadef.pdf
    • http://kfbi.ru/content/file/rutuxopixenidew.pdf
    • https://namastehealth.in/wp-content/plugins/super-forms/uploads/php/files/eiqev8crpsdmtsnt9d51npq94o/nokidogagus.pdf
    • https://pikewallis.no/wp-content/plugins/formcraft/file-upload/server/content/files/160957da5adf38---zukalotopilamolod.pdf
    • http://przychodnia-felinskiego.pl/uploads/editor/file/54410290715.pdf
    • http://christembassydocklands.org/wp-content/plugins/super-forms/uploads/php/files/15fc8ed7536e6faec228769db4b682d2/76923499032.pdf
    • https://www.energetisch-therapeut-estie.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160a06aae20ead---rinewozabupetofugiganis.pdf
    • http://julieesteban.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c24dd8e6bc2---57532617177.pdf
    • http://chi-kara.net/userfiles/file/58881062359.pdf
    • https://pima-alarms.rs/slicice/file/33023145121.pdf
    • http://beveragesgs.com/userfiles/file/purowituxojuvabanurofa.pdf
    • http://drinkandshrink.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/160c1f44b76954---vojasupivazikupe.pdf
    • https://www.chauffeur-prive-nice.fr/wp-content/plugins/formcraft/file-upload/server/content/files/160d7454b80b3f---toxox.pdf
    • https://www.chauffeur-prive-nice.fr/wp-content/plugins/formcraft/file-upload/server/content/files/1606c83d7ebda7---lukunijisapetiwawowoguz.pdf
    • http://akvari-um.ru/userfiles/file/50698007902.pdf
    • https://rfcorporation.net/wp-content/plugins/super-forms/uploads/php/files/8926ede1fc80b5fe288375b75530880b/56969358257.pdf
    • http://crosswaysrecruitment.com/userfiles/file/94764651447.pdf
    • http://kennyre.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c5002e07bf6---pireluzidesike.pdf
    • https://postscriptproductions.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c1e97c61663---15694619124.pdf
    • http://warraichmeats.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607e37754fbed---20006877045.pdf
    • https://www.modianodesign.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a0231d11cc1---50712354463.pdf
    • 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_off0001557d.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x1557D 16792 bytes
font_01_sfnt_off00016d8f.bin
fabc04ca2019788345205b3ab164cde11433a1e914a2a09d2ce76d29422d8afe
pdf-font-stream PDF embedded font (sfnt) at offset 0x16D8F 17108 bytes
font_02_sfnt_off00019972.bin
a8ba65ecfc7eae1f72ec3813ef4985d77fad7bd5b28b814a95d0b80b21804c91
pdf-font-stream PDF embedded font (sfnt) at offset 0x19972 10820 bytes