Malicious PDF — malware analysis report

Static analysis result for SHA-256 4c8b956efd75a8f2…

MALICIOUS

PDF

82.0 KB Created: 2021-09-17 21:06:02 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: 68b62ff0cb8ce7735b742984c4220dea SHA-1: 9645327940c47960cb1244caf9f596f5b7724488 SHA-256: 4c8b956efd75a8f2d3d63ef6bd7704f0b8e6e949b942f1b31178d8b8bbd77454
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. It contains numerous external links, many pointing to compromised CMS uploads or disposable hosting, suggesting a link farm designed to redirect users. The presence of these links and the overall detection indicate a likely phishing or malware distribution attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9960

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://classconnbio.com/img-jacson/files/37993919760.pdf In PDF document text
    • http://knowleangling.co.uk/ckfinder/userfiles/files/gonofidimuzobiz.pdfIn PDF document text
    • https://nobelboya.com/userfiles/file/tokewomivib.pdfIn PDF document text
    • http://iamsoldierfit.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613397a43e2e8---3861092284.pdfIn PDF document text
    • https://www.wemservice.com/ckfinder/userfiles/files/97748918532.pdfIn PDF document text
    • http://saint-party.com/media/file/62669863326.pdfIn PDF document text
    • http://bunny888.com/ckfinder/userfiles/files/petelogevimezovul.pdfIn PDF document text
    • https://alasclub.gr/neuro/ckfinder/userfiles/files/xaxodenad.pdfIn PDF document text
    • http://argentum.com/wp-content/plugins/super-forms/uploads/php/files/u4nabj0cs54hkto90t3qihkdur/bimanos.pdfIn PDF document text
    • http://asu78.ru/userfiles/file/givuxejejawesexodubomes.pdfIn PDF document text
    • https://linkevicius.com/upload/galery/file/37396314686.pdfIn PDF document text
    • http://uniradioweb.info/userfiles/files/wodufosifinofusezijipa.pdfIn PDF document text
    • https://rsebolivia.org/userfiles/file/89847319528.pdfIn PDF document text
    • http://zelene-centrum.cz/webpagebuilder/ckfinder/userfiles/files/lenujebed.pdfIn PDF document text
    • http://saxonrt.hu/img/userfiles/files/merapatumusufe.pdfIn PDF document text
    • http://www.fsnn.se/wp-content/plugins/formcraft/file-upload/server/content/files/1613a9034311df---88145415936.pdfIn PDF document text
    • https://gospel-streams.com/asset/ckfinder/userfiles/files/99995449528.pdfIn PDF document text
    • http://rafaelstore.ru/upload/files/7070216679.pdfIn PDF document text
    • http://lnyuanzong.com/uploads/files/20210903200024.pdfIn PDF document text
    • http://eau-msu.ru/ckfinder/userfiles/files/45017499549.pdfIn PDF document text
    • http://vtracauto.com/wp-content/plugins/formcraft/file-upload/server/content/files/16137de0bbecbe---27505004187.pdfIn PDF document text
    • http://cjmfgxfollow.morefriendship.com/upload/files/2425800700.pdfIn PDF document text
    • https://www.conkite.com/wp-content/plugins/super-forms/uploads/php/files/b308ea7a1cd387c3cab897e05cd55765/29010940563.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/A3Ryygt5BCM/uplcv?utm_term=android+black+screenPDF 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_off0000dbf5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDBF5 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f407.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF407 18444 bytes
SHA-256: c4824095529a9922dfa3560f2adbaa7f892ed1e45437550e6c1c2168467b5941
font_02_sfnt_off0001232c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1232C 10476 bytes
SHA-256: d94742070534ad1cb8d4b585504c512a6f178fb240c9b3dce0cf794b9bca94be