Malicious PDF — malware analysis report

Static analysis result for SHA-256 d833cf99c4f3079e…

MALICIOUS

PDF

93.1 KB Created: 2021-07-01 14:25:58 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-14
MD5: 38f828a6ef1c96bae58347952ccaac81 SHA-1: d5b47eabf50885f54987aad39999f5b0b38ed082 SHA-256: d833cf99c4f3079e4da13c45146feb17d68ec29069c602c92ed4d142184943ab
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains a large number of links, many pointing to compromised CMS uploads or disposable hosting, suggesting a link farm or SEO manipulation tactic. The ML classifier and ClamAV detection strongly indicate malicious intent, likely related to phishing or distributing further malware. No scripts were extracted, but the structure and URL patterns are indicative of malicious activity.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9929

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://handbook.hu/upload/page/file/getag.pdf In PDF document text
    • https://sanidom.pl/img/file/robabi.pdfIn PDF document text
    • http://architettorobertafasola.eu/userfiles/files/ramewitajomemiwekakude.pdfIn PDF document text
    • http://hoangnamjsc.com/upload/files/92438934797.pdfIn PDF document text
    • http://hndgyl.com/v15/Upload/file/2021682157196587.pdfIn PDF document text
    • https://cissud.com/uploads/ck_editor/files/89548257286.pdfIn PDF document text
    • https://autoschiller.de/wp-content/plugins/formcraft/file-upload/server/content/files/16075cdc56dedf---vobiridezerekudaliw.pdfIn PDF document text
    • https://strechybenesov.cz/content/padugalovareborok.pdfIn PDF document text
    • https://nepalaviationmuseum.com/userfiles/files/vedinomowarapebavekutedo.pdfIn PDF document text
    • https://lamaisonducoeur.ca/upload/editor/file/zogedubowef.pdfIn PDF document text
    • https://psychotherapie-dr-albrecht.de/wp-content/plugins/formcraft/file-upload/server/content/files/16073f7c66152d---gupufomuma.pdfIn PDF document text
    • http://pulsrmedia.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bfde4dbeca2---nawujizanimebebila.pdfIn PDF document text
    • https://palcev.ru/userfiles/file/72242662063.pdfIn PDF document text
    • http://www.pilonidalsinus.gen.tr/wp-content/plugins/formcraft/file-upload/server/content/files/1606cb79c6df2d---45034634004.pdfIn PDF document text
    • http://kaupa.cz/userfiles/file/bugani.pdfIn PDF document text
    • http://gf-location.fr/wp-content/plugins/formcraft/file-upload/server/content/files/16088288c49917---bojowipone.pdfIn PDF document text
    • https://rimsball.com/ckfinder/userfiles/files/63499420130.pdfIn PDF document text
    • https://alkhairi.co.uk/wp-content/plugins/super-forms/uploads/php/files/205d1caabc3d0308cddfd847d3db75b7/limonala.pdfIn PDF document text
    • http://makaeximworld.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608ada24781c9---50384239012.pdfIn PDF document text
    • http://paymentsbusiness.ca/wp-content/plugins/formcraft/file-upload/server/content/files/160a5e0b6d09c1---jozogalubosexozav.pdfIn PDF document text
    • http://khochailo.com/upload/ck/files/nafefikus.pdfIn PDF document text
    • http://salonlomi.pl/wp-content/plugins/formcraft/file-upload/server/content/files/160b4bc10adf45---pulamukowedebilib.pdfIn PDF document text
    • https://heritagelogs.com/wp-content/plugins/super-forms/uploads/php/files/jlf7knooto4uh3m8log6vbisig/17345851334.pdfIn PDF document text
    • https://beribuket.ru/wp-content/plugins/super-forms/uploads/php/files/58e62275b9d63c52cf74960dd3e80b4d/34244892976.pdfIn PDF document text
    • https://grup-insaat.com/userfiles/file/misejadu.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/fzgW7-mxBc0/uplcv?utm_term=warrior+class+quests+wow+classicPDF 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_off00010c7e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10C7E 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00012495.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12495 10444 bytes
SHA-256: f2e5718d4d1f6ece2143120a2a9ace783cae0a14ee6c34c1b2feb49bbbca1cd1
font_02_sfnt_off00013c80.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13C80 16488 bytes
SHA-256: a4d50addd36463688b6e725db9875e7b6614985b81ea0145e29215bad2a87595