Malicious PDF — malware analysis report

Static analysis result for SHA-256 2140d7ee8e525649…

MALICIOUS

PDF

71.3 KB Created: 2021-09-03 10:26:43 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: e60222607cddb2cd90d3ca181f5a3375 SHA-1: 345b865f0e51ab79382d9ea63308f6030b130214 SHA-256: 2140d7ee8e525649a96ffa49a1177da40a359ebe86bdbd534e9f946546ec77df
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file is identified as malicious by ML classifiers and ClamAV. It contains numerous URLs, many pointing to compromised websites or disposable hosting, suggesting a link farm designed to redirect users. The presence of PDF_SEO_DISPOSABLE_LINK_FARM and PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM heuristics indicates a tactic to obscure malicious links. The primary attack pattern involves directing users to external PDF files, likely as a phishing or malware distribution vector.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9982

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://smidgel.ru/uplcv?utm_term=cell+membrane+and+tonicity+worksheet+key.pdf PDF link annotation
    • http://odumakus.com/uploads/files/17882261669.pdfIn PDF document text
    • http://peusch.lu/userfiles/files/fuboted.pdfIn PDF document text
    • http://www.associatedomains.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608c6b8bb0dfa---wawadixisagatu.pdfIn PDF document text
    • http://osoboebludo.com/ckfinder/userfiles/files/fikiwasubawe.pdfIn PDF document text
    • http://lorichphoto.com/pictures/file/67861860188.pdfIn PDF document text
    • https://gabconstruction.com/ckfinder/userfiles/files/bobololije.pdfIn PDF document text
    • http://erictex.com/ufiles/files/35124430692.pdfIn PDF document text
    • https://permargi.com/files/galeria/files/65873334462.pdfIn PDF document text
    • https://zenmobile.in/jaipriyart/uploads/files/1108525108.pdfIn PDF document text
    • https://reparationmobile.net/userfiles/file/29738407941.pdfIn PDF document text
    • https://refour.dk/wp-content/plugins/super-forms/uploads/php/files/6fdfa01d822fd6f7a4e83743532f9f62/terekabenojowivufakukewod.pdfIn PDF document text
    • http://riccaassociati.eu/userfiles/files/47471829419.pdfIn PDF document text
    • http://www.gonouvellezelande.com/files/55897486200.pdfIn PDF document text
    • https://www.zaantraining.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160e83dacdd086---38857697013.pdfIn PDF document text
    • http://telegid.tv/userfiles/files/17352299594.pdfIn PDF document text
    • http://srtprogetti.eu/userfiles/files/33291642063.pdfIn PDF document text
    • http://aucoindeshalles.com/menu/file/vemim.pdfIn PDF document text
    • http://neuragen.ca/wp-content/plugins/formcraft/file-upload/server/content/files/160816d0cdd359---mujopawagilonawu.pdfIn PDF document text
    • https://agape4u.org/userfiles/file/61006780811.pdfIn PDF document text
    • http://buergerforum-tirol.at/file/19459303848.pdfIn PDF document text
    • http://velo.hu/UserFiles//file/69516090067.pdfIn PDF document text
    • https://bxthirteen.wpengine.com/wp-content/plugins/super-forms/uploads/php/files/ee623e964b1f636f5cb8ff11fea56315/5194565131.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_off0000b54b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB54B 15548 bytes
SHA-256: 0825b3f50054fe508edcca3de45a1c3c25c984bdac8d1aa6acbd6757c869f7df
font_01_sfnt_off0000dcd6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDCD6 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000f4ed.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF4ED 11412 bytes
SHA-256: 79497057a635c515bdd5345d673110675611e63d4b716479042d7cfc5eb3280c