Malicious PDF — malware analysis report

Static analysis result for SHA-256 4887ca7bc767c141…

MALICIOUS

PDF

81.5 KB Created: 2021-09-21 04:22:05 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: c1a5516aa7cfd5efae9ca757759a6e63 SHA-1: f41cd5183038baf77034c575c4da866b81045dd0 SHA-256: 4887ca7bc767c141d8978ba1469e43668008bbfe0a92c541b028b0bc1e6e7cab
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many pointing to disposable or compromised domains, indicating a link farm designed to lure users to potentially malicious sites. The ClamAV detection and ML classifier strongly suggest malicious intent, likely phishing or malware distribution. The file's structure and URL patterns align with techniques used to deliver malicious content via spearphishing attachments.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

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://archism.ru/uplcv?utm_term=how+do+i+get+different+emojis+on+my+phone PDF link annotation
    • http://zh-huaxun.com/uploadfiles/files/dagawoseki.pdfIn PDF document text
    • http://revize-elektro.info/UserFiles/File/92798976132.pdfIn PDF document text
    • http://labradory.pl/file/resotekewopamatugopeg.pdfIn PDF document text
    • http://topflexsports.com/uploads/woruteribuwiwep.pdfIn PDF document text
    • https://chungangroup.com/uploads/files/202109091749228950.pdfIn PDF document text
    • https://elger.cz/fckphotos/file/50971937869.pdfIn PDF document text
    • http://roletyhanarol.pl/files/file/lagupu.pdfIn PDF document text
    • http://thanhlamresort.vn/wp-content/plugins/formcraft/file-upload/server/content/files/1613deb7d426fe---54116523153.pdfIn PDF document text
    • http://roosprommenschenckelfoundation.nl/userfiles/file/95589918007.pdfIn PDF document text
    • http://kirks-pool.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614903508eca2---93470640966.pdfIn PDF document text
    • http://nigerseedindia.com/uploads/tezelaxezikagewazazi.pdfIn PDF document text
    • http://hotstamping.pl/files/file/giketarabisuvufamapeje.pdfIn PDF document text
    • http://progfin.pl/userfiles/file/nujoguposumar.pdfIn PDF document text
    • http://klingende-zeder.de/wp-content/plugins/formcraft/file-upload/server/content/files/161403d077796d---44556576165.pdfIn PDF document text
    • https://linardi.ru/files/file/42823277273.pdfIn PDF document text
    • https://csodamalom.hu/files/files/zeroz.pdfIn PDF document text
    • http://exms.fr/sites/default/files/file/69554467069.pdfIn PDF document text
    • http://zenithmetals.com/files/42114361679.pdfIn PDF document text
    • https://resepangka.org/contents/files/gaxigipefuzaduneketisadax.pdfIn PDF document text
    • https://bongkartuantakur.com/contents/files/61645817238.pdfIn PDF document text
    • https://saatyapi.com/upload/ckfinder/files/73809904340.pdfIn PDF document text
    • https://secolink.sk/userfiles/file/55372704222.pdfIn PDF document text
    • http://mp-journal.com/media/file/72127997833.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_off0000d88b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD88B 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f0a2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF0A2 11056 bytes
SHA-256: f179e130da82ce218ba41bced73459dca65ee16ac41ca084fbdd75bfe7a73ce4
font_02_sfnt_off000109f4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x109F4 18048 bytes
SHA-256: da804989f402a18b2ea6b0a7ec6d1564aa5d647e833b119d12a461fb704160ee