Malicious PDF — malware analysis report

Static analysis result for SHA-256 cf28d7f261e202d9…

MALICIOUS

PDF

83.0 KB Created: 2021-07-16 15:45:55 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: ddb0a6f4dbbf3b35beed2ec3b9d69cdd SHA-1: 5f5a2c88b0d5dd8fe2eae122892436f4014c5104 SHA-256: cf28d7f261e202d99e685d7322453c8fdecca940401e8d5b9922857ccc42ea0f
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The PDF contains numerous external links, many pointing to compromised CMS upload directories or disposable hosting, indicating a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or distributing further malware. No scripts were extracted, but the structure and URL patterns are indicative of a malicious PDF.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9964

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://chcial.ru/uplcv?utm_term=confluence+tooltip+macro
    • http://www.jindatunnel.com/up_files/file/92383306480.pdf
    • https://www.abaco-engineering.it/wp-content/plugins/formcraft/file-upload/server/content/files/1608e46bd964bc---6414401721.pdf
    • https://autoschiller.de/wp-content/plugins/formcraft/file-upload/server/content/files/1609b636f90a1b---61101755338.pdf
    • http://skupka23.ru/upload/m/viwepet.pdf
    • https://controlcert.se/wp-content/plugins/formcraft/file-upload/server/content/files/1609ffb33f12e5---sujerobizopu.pdf
    • https://hzautomatisering.nl/userfiles/file/fokekegatugoxazutagux.pdf
    • https://olgapopovaphoto.com/wp-content/plugins/super-forms/uploads/php/files/3825b943a6080e12566a435061bb27e8/72522568200.pdf
    • https://juhaszautovill.hu/userfiles/file/mawopagobarukevibedaxix.pdf
    • https://www.spoton.pet/wp-content/plugins/super-forms/uploads/php/files/2aq6ltvh6jl3bsvkr6c6scdgv8/19144196688.pdf
    • https://sckstone.com/wp-content/plugins/super-forms/uploads/php/files/24ff525813f55e8412e0bd12bfcbfd5e/3825407831.pdf
    • http://maytinhtuyenquang.com/home/maytinhtuy/domains/maytinhtuyenquang.com/public_html/images/file/tirowizujowewamejegabuwuz.pdf
    • https://member-amz-seller-system.de/wp-content/plugins/super-forms/uploads/php/files/a1eaf0ab7040ee98a713753e9743aa57/11906340217.pdf
    • https://www.d-table.com/wp-content/plugins/super-forms/uploads/php/files/dae952350fdf6a4748e414460d005708/wetegezotiviroralo.pdf
    • http://networkinglikepro.com/ckfinder/userfiles/files/58346846427.pdf
    • http://studiogalata.it/userfiles/files/68537140926.pdf
    • https://www.revistadefiesta.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606ea3fe314b4---jenasesavigi.pdf
    • https://www.18fire.com/wp-content/plugins/super-forms/uploads/php/files/6992fe2dc8f7448d0cb127ca6335bbde/26633343913.pdf
    • https://discoverthesky.it/file/dekize.pdf
    • https://www.officinadelgustoroma.com/wp-content/plugins/super-forms/uploads/php/files/e178fac88c413e18d055983106c0742d/66347296259.pdf
    • http://sakaryakasaplarodasi.org/userfiles/file/latetabolagexoras.pdf
    • https://admonks.ru/wp-content/plugins/super-forms/uploads/php/files/7489d08266b65ddcb32f775f8bddcfc4/41044543360.pdf
    • https://www.medipratik.com/wp-content/plugins/formcraft/file-upload/server/content/files/16075cf305f076---58589511630.pdf
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000e4c3.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xE4C3 16792 bytes
font_01_sfnt_off0000fcda.bin
80066695a634b71c242281f9ae4d6ee971c5b4ac97f4d55a1e7f8e47c1ee2d55
pdf-font-stream PDF embedded font (sfnt) at offset 0xFCDA 10604 bytes
font_02_sfnt_off0001150b.bin
0fc2e36406e8cf37a7ab4661869000aac65c3731c296a4ceb5d654f9c614841b
pdf-font-stream PDF embedded font (sfnt) at offset 0x1150B 16268 bytes