Malicious PDF — malware analysis report

Static analysis result for SHA-256 b1c7bd56135031a5…

MALICIOUS

PDF

71.2 KB Created: 2021-09-05 14:35:43 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: 405b9731221f0212222d01d72127c5f0 SHA-1: 81cdfc8696d5787b9196099e37cd43e89d6d78e7 SHA-256: b1c7bd56135031a5de44116df7ba9758aa4674c8c59dcb6cd939c7e5e1a4d56f
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF document was flagged by ML classifiers and ClamAV as malicious, indicating a phishing or trojan payload. It contains a link farm with numerous URLs pointing to compromised websites and disposable hosting, likely intended to redirect users to malicious content. While no scripts were directly extracted, the PDF structure and embedded links suggest an attempt to lure users to external resources, aligning with spearphishing tactics.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9992

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://doudou.tw/userfiles/files/niliwitizeguf.pdf In PDF document text
    • https://sgdivorcelawyers.com/wp-content/plugins/super-forms/uploads/php/files/4fcc62a0a38a84a7487c353816c9b3d6/96630691602.pdfIn PDF document text
    • http://www.psoevalledeabdalajis.es/ckfinder/userfiles/files/47378328533.pdfIn PDF document text
    • http://ekotop.eu/userfiles/file/bubut.pdfIn PDF document text
    • http://hellnocancershow.com/wp-content/plugins/formcraft/file-upload/server/content/files/16080af90623c6---62994642631.pdfIn PDF document text
    • https://infotechb2blite.com/bot/ckfinder/uf/files/14335431484.pdfIn PDF document text
    • https://www.audioclinica.pt/wp-content/plugins/super-forms/uploads/php/files/p66q2u24fcue058tb18mdih38p/wuveveze.pdfIn PDF document text
    • https://davidfauquemberg.com/home/fauquemb/david/bbdg_site/userfiles/file/gamavakavewiboragoditazu.pdfIn PDF document text
    • https://12shio1.com/contents//files/18153797684.pdfIn PDF document text
    • https://aashianarealty.com/file/ninizuxalijijogevevuworu.pdfIn PDF document text
    • http://teraval.cz/res/file/zezejevalabudar.pdfIn PDF document text
    • https://sieompaysdebray.fr/lesiom/txt/imgadmin/file/84067051678.pdfIn PDF document text
    • http://baanpowertrain.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a4223cdb278---89741462803.pdfIn PDF document text
    • http://harchovyk.com/userfiles/file/bufugawasejutujuke.pdfIn PDF document text
    • http://www.lightingandhvacexpo.com/wp-content/plugins/super-forms/uploads/php/files/687e2e67aae9e0a76121e1a9d9523c9b/defosi.pdfIn PDF document text
    • https://mercedesmazo.es/wp-content/plugins/formcraft/file-upload/server/content/files/160821f9ef1bdc---87111484257.pdfIn PDF document text
    • http://www.guaitoli.eng.br/wp-content/plugins/formcraft/file-upload/server/content/files/160c2881c57064---jekiz.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/DOqCt-cVA4I/uplcv?utm_term=worksheets+for+synonyms+and+antonyms+4th+gradePDF 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_off0000b4d2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB4D2 16168 bytes
SHA-256: 7f06655f773c41a1c113f744146f63936421e66f59a28c8b7889a1f352779c86
font_01_sfnt_off0000de86.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDE86 10940 bytes
SHA-256: 4afe1ccd3a31b9ab81c4961015ea6f01df5d510abee788207d944ca28d7f59fb
font_02_sfnt_off0000f79b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF79B 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1