Malicious PDF — malware analysis report

Static analysis result for SHA-256 90eff5342f407f43…

MALICIOUS

PDF

72.5 KB Created: 2021-10-01 06:21:28 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: 29c2efe09efa0566459802644a988d6d SHA-1: 62caa7087e51bad3d37e21d17a66bb90b93dc542 SHA-256: 90eff5342f407f439b30a0d9fa390e18389a5b71fb9046523d21e246065dfa90
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF file was flagged by ML classifiers and ClamAV as malicious, indicating a high likelihood of malicious intent. It contains numerous embedded URLs, many pointing to compromised WordPress sites or disposable hosting, suggesting it functions as a link farm. The presence of these links, combined with the 'PDF_SEO_DISPOSABLE_LINK_FARM' heuristic, indicates the document's primary purpose is to redirect users to external malicious sites, likely for phishing or malware delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9985

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://inwebjor.ru/uplcv?utm_term=mobile+dj+mixer+apk+download PDF link annotation
    • https://www.syah.org/wp-content/plugins/super-forms/uploads/php/files/6048c6639490107fc7341e9dfd4e43a3/95524715306.pdfIn PDF document text
    • https://nam.it/wp-content/plugins/formcraft/file-upload/server/content/files/1612ee666df8f7---tukaxamuj.pdfIn PDF document text
    • https://hiroyoung.com/data/files/vowagagepuwem.pdfIn PDF document text
    • http://sunnyten.net/userData/board/file/97229347061.pdfIn PDF document text
    • https://www.tri-or.fr/tri-or/ckfinder/userfilesfiles/23483065834.pdfIn PDF document text
    • http://locthanhroyal.com/upload/files/zefurumozipi.pdfIn PDF document text
    • https://flomogroup.com/upload/files/20905201089.pdfIn PDF document text
    • http://ryanoomen.nl/uploadimages/files/66428806307.pdfIn PDF document text
    • https://al-farh-iq.com/upload/userfiles/file/mabavubivipilum.pdfIn PDF document text
    • http://asijskepotraviny.cz/files/file/97511262915.pdfIn PDF document text
    • http://caerulumpharma.com/upload/files/xudonugobotalilax.pdfIn PDF document text
    • https://lisacutler.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614db15d39b3a---69298000094.pdfIn PDF document text
    • http://asia-test.informacittadino.net/media/files/15085454222.pdfIn PDF document text
    • http://lyzebrno.cz/userfiles/file/90422408269.pdfIn PDF document text
    • https://www.ayersworthglen.com/wp-content/plugins/formcraft/file-upload/server/content/files/16138a6129ae32---zusawekek.pdfIn PDF document text
    • http://osteriailgalloelinnamorata.com/userfiles/files/87689202138.pdfIn PDF document text
    • https://muratay.nl/userfiles/file/96592005501.pdfIn PDF document text
    • http://condosworld.com/abisol1/userfiles/files/83582677214.pdfIn PDF document text
    • http://ekopaczka.pl/imgbrama/files/rarokulodokalep.pdfIn PDF document text
    • http://www.vnv.nu/admin/library/ckfinder/userfiles/files/57249188493.pdfIn PDF document text
    • http://hcvitamin.com/webroot/img/files/37066496283.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_off0000b32b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB32B 10832 bytes
SHA-256: d98a32c385e07d83a26c90ac8330a574f00079770f2ceaed31efabea614f3352
font_01_sfnt_off0000cbdd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCBDD 18904 bytes
SHA-256: 3bf99e65a30980404754a5ee0080d745711be939536f11ecaae50f0525719b71
font_02_sfnt_off0000fc68.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFC68 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1