Malicious PDF — malware analysis report

Static analysis result for SHA-256 4a68a3870238ae17…

MALICIOUS

PDF

72.7 KB Created: 2021-09-05 08:05:44 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: ad6fe07f55d95778f78dc3c5e8bcdb1e SHA-1: 1bbccd8f8e2cd0cd92b313e23575417274e3a692 SHA-256: 4a68a3870238ae17c8b1420d6b6e9c1a909c0c294dd0e4ac946a3296a74123c1
156 Risk Score

Malware Insights

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

The file is a PDF containing numerous embedded URLs that point to other PDF files hosted on various websites. Several heuristics indicate these URLs are part of a link farm, with some pointing to compromised CMS uploads. The ML classifier and ClamAV detection strongly suggest malicious intent, likely related to phishing or malware distribution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9985

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://www.conkite.com/wp-content/plugins/super-forms/uploads/php/files/504cd76724f980f72c46c3b75805c70e/69378085119.pdf In PDF document text
    • http://grandinspirations.com/clients/75274/File/93370120096.pdfIn PDF document text
    • https://www.gurkhasfinance.com.np/ckfinder/userfiles/files/13089354639.pdfIn PDF document text
    • https://laneopx.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607f1b9230f70---seduzamezojemazatodije.pdfIn PDF document text
    • https://ag-concept.ru/wp-content/plugins/super-forms/uploads/php/files/c27cc89899a4e55751a47802d4e96f4f/82976001079.pdfIn PDF document text
    • http://shannonlakeestates.org/fck_images/file/94138473360.pdfIn PDF document text
    • http://flagrant-desir.com/userfiles/file/worugabiwifuru.pdfIn PDF document text
    • http://drinkandshrink.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/160a21663707c2---71489922578.pdfIn PDF document text
    • https://e-uchebnici.com/img/file/36259500373.pdfIn PDF document text
    • http://havefuntogether.com/image/upload/File/8376902530.pdfIn PDF document text
    • http://andreaslasnik.com/data/files/mibisuxemavamexuv.pdfIn PDF document text
    • http://nurugelexport.com/ckfinder/userfiles/files/6175322970.pdfIn PDF document text
    • https://dtcprojects.com.au/wp-content/plugins/super-forms/uploads/php/files/4b3kl5cbae1orl194g0n652ev3/vunopojugesinubebukagu.pdfIn PDF document text
    • https://toptenstudy.com/upload/files/BodyFile__60FBAA257D68F.pdfIn PDF document text
    • http://yer-krasnodar.ru/ckfinder/userfiles/files/42883446911.pdfIn PDF document text
    • https://nuregio.de/wp-content/plugins/formcraft/file-upload/server/content/files/16077ad4169dca---bilivadupusavamutozew.pdfIn PDF document text
    • https://fnb-concepts.com/images/uploads/files/76801281240.pdfIn PDF document text
    • http://thaoduocquyhiem.com/userfiles/image/file/94995226987.pdfIn PDF document text
    • http://kxnjl.com/userfiles/files/83383219584.pdfIn PDF document text
    • http://www.blueoak.fr/image/file/44624070815.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/DOqCt-cVA4I/uplcv?utm_term=socomec+atys+pm+manualPDF link annotation
    • http://www.thaiticketmajor.com/static/imgUpload/files/nevijinavemoxibizapu.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_off0000b9e4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB9E4 16720 bytes
SHA-256: fcbe1f0c36a4be1167feaa8eb8aee8064f61bbcafa310bbd007a024154b64d88
font_01_sfnt_off0000e4c0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE4C0 10632 bytes
SHA-256: 12f8d1ff14381c7e32d0f81cbc5919024eb42f067923144060250115a748f5dd
font_02_sfnt_off0000fd26.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFD26 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1