Malicious PDF — malware analysis report

Static analysis result for SHA-256 8603cf3d64def153…

MALICIOUS

PDF

70.5 KB Created: 2021-06-20 09:38:12 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-11
MD5: 61ac6412d8318fda41402cfbf7221e36 SHA-1: 70f4d899c047a6d8b91f57d4a4691dd7cf115b3a SHA-256: 8603cf3d64def15341850b0eb7d064cc21c4d53cf93ea10bc7475a225912b675
156 Risk Score

Malware Insights

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

This PDF file was detected as malicious by ML classifiers and ClamAV, indicating a phishing or malware distribution intent. It functions as a link farm, containing numerous URLs pointing to compromised WordPress uploads and other disposable hosting, likely to redirect users to malicious content. The document body is heavily obfuscated and contains metadata suggesting it was generated by wkhtmltopdf.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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://antifftech.com/uploadfile/file/%5C/2021050319431815.pdf In PDF document text
    • https://www.chortho.co.uk/wp-content/plugins/super-forms/uploads/php/files/6kpqiua18gln013ivuelnkeiun/6773807438.pdfIn PDF document text
    • https://quickonboarding.com/wp-content/plugins/super-forms/uploads/php/files/246451af3e85c191356eab4d018a6a04/60788876934.pdfIn PDF document text
    • http://driver-jazda.pl/upload/file/3332449701.pdfIn PDF document text
    • http://limpiasol.com/wp-content/plugins/formcraft/file-upload/server/content/files/16073e2e5dec2d---gileruvu.pdfIn PDF document text
    • http://www.psstrecno.sk/wp-content/plugins/formcraft/file-upload/server/content/files/160a7949a13190---vilolav.pdfIn PDF document text
    • http://xn----8sbpvg0afdbe.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/ul8rb087f18um76r3uo0h04ak6/raloxajuxowodufewumuvosan.pdfIn PDF document text
    • http://gfhs1978reunion.com/clients/56625/File/22841796838.pdfIn PDF document text
    • https://storage-in-motion.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c2ef348711d---82834664582.pdfIn PDF document text
    • https://siyata.co.il/wp-content/plugins/formcraft/file-upload/server/content/files/1608554ca080c7---jolap.pdfIn PDF document text
    • https://www.parkgest.ch/wp-content/plugins/formcraft/file-upload/server/content/files/1609b6cff27d7f---deroguka.pdfIn PDF document text
    • http://bridgesonthepark.com/wp-content/plugins/formcraft/file-upload/server/content/files/16073c5fd3c596---dikowefiniwajimubisebej.pdfIn PDF document text
    • http://getawaynewzealand.co.nz/wp-content/plugins/formcraft/file-upload/server/content/files/160ca4bb55bcce---gagitidarinikozavunog.pdfIn PDF document text
    • http://www.ncstarim.com.tr/wp-content/plugins/super-forms/uploads/php/files/t9rc1v8hsnbfhvjja2ce1908q5/22262101933.pdfIn PDF document text
    • https://shrmivirtual.org/wp-content/plugins/super-forms/uploads/php/files/48f1c949556f910502fc94ecad26adf7/memolawinotimi.pdfIn PDF document text
    • http://2girlstrippin.com/wp-content/plugins/formcraft/file-upload/server/content/files/160afd68a96bd5---lubopuvigujepigumo.pdfIn PDF document text
    • https://adiwirawanbali.com/wp-content/plugins/super-forms/uploads/php/files/80388058c7563e65bac002d8679cd19a/66660746104.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/FevRqgeaUVY/uplcv?utm_term=physics+of+scientists+and+engineersPDF 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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000d4a0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD4A0 5352 bytes
SHA-256: f050fa5b9bf1ea0f89dcebe69e58a8d2b27f7aae33785d5d003c10e76d696209
font_01_sfnt_off0000e6e0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE6E0 10752 bytes
SHA-256: 4b8fd555db309031c5e0bf2d6c19ac12b2df59da8dacc12f8bba1e731b95c8d9