Malicious PDF — malware analysis report

Static analysis result for SHA-256 ec83504d25fe406a…

MALICIOUS

PDF

81.9 KB Created: 2021-09-16 11:09:35 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-31
MD5: 5c4cb8d47e8512bc18293a0bdb441c8e SHA-1: 9d88b3f0cd5cab06e11365cc8b3a8c68bd949a28 SHA-256: ec83504d25fe406a079418bf7a6e8fbc92effde82db4fb0defb325181acb94ff
164 Risk Score

Malware Insights

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

The file is identified as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It contains a link farm pointing to compromised WordPress uploads and other disposable hosting, suggesting an attempt to distribute malware. The presence of a 'download button' heuristic further supports the lure-based attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9955

Heuristics 7

  • 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.
  • Visual download / call-to-action button lure low SE_DOWNLOAD_BUTTON
    Document contains a call-to-action phrase ('Click here to download', 'Download Now', etc.) — low-signal unless other findings point to a malicious workflow
  • 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://gyndoktors.de/ckfinder/userfiles/files/pigud.pdf In PDF document text
    • http://klubalfa.org/img/userfiles/file/3417437206.pdfIn PDF document text
    • http://se-ty.ru/uploads/userfiles/file/mikegifurapimu.pdfIn PDF document text
    • https://www.tessilgiada.it/wp-content/plugins/formcraft/file-upload/server/content/files/1613efb02936df---51185744626.pdfIn PDF document text
    • http://webinaris.org/ckfinder/userfiles/publics/files/88226107561.pdfIn PDF document text
    • https://cplastik.com/data/cms/file/kosoj.pdfIn PDF document text
    • http://rtm-plus.com/ckfinder/userfiles/files/mexizavidudupewo.pdfIn PDF document text
    • https://wspaperbag.com/userfiles/file/14757620825.pdfIn PDF document text
    • http://realfootball.gr/userfiles/file/1968575799.pdfIn PDF document text
    • https://audreyheselmans.com/_files/file/99734153610.pdfIn PDF document text
    • http://grupposcorcia.it/userfiles/files/18389434550.pdfIn PDF document text
    • https://opescom-store.com/uploads/FCK_files/file/68785119347.pdfIn PDF document text
    • http://diegogenna.it/userfiles/files/61146626494.pdfIn PDF document text
    • http://kimsanghun.com/upload/userfiles/file/2021991945197565.pdfIn PDF document text
    • https://pomacanthe-art.fr/imagebeforeafter/files/21266460569.pdfIn PDF document text
    • https://roadtoring.com/wp-content/plugins/super-forms/uploads/php/files/584cc60dc1c617600c8335f14c37835e/91608401955.pdfIn PDF document text
    • http://pretaporter-pegah.com/userfiles/file/diwadepawu.pdfIn PDF document text
    • http://lichnyiybrand.ru/wp-content/plugins/formcraft/file-upload/server/content/files/16135d5186bf47---tesuko.pdfIn PDF document text
    • http://origo.ws/userfiles/file/13186592360.pdfIn PDF document text
    • http://www.florentmaussion.net/userfiles/File/72368335998.pdfIn PDF document text
    • https://www.studiorosaliabusco.it/ckfinder/userfiles/files/63708271936.pdfIn PDF document text
    • http://coquicart.com/ckeditor/ckfinder/core/connector/php/uploads/files/nugizosebefujuliwa.pdfIn PDF document text
    • http://www.jindatunnel.com/up_files/file/busowagikex.pdfIn PDF document text
    • http://nathulaldasptti.com/ckeditor/ckfinder/userfiles/files/vitemilufedomivogikif.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/1KS0DP0cxss/uplcv?utm_term=cricket+championship+2+mod+apkPDF 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_off0000dc45.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDC45 17404 bytes
SHA-256: b4be0546dd2a5d50e05e43b947e2b1d22a9279b84e05f5129d36728fc1008317
font_01_sfnt_off00010901.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10901 10976 bytes
SHA-256: 6c92178ac6f6f072c59b5c827138b3450a7f9572497b589e4d1049b3d980f391
font_02_sfnt_off0001226a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1226A 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1