Malicious PDF — malware analysis report

Static analysis result for SHA-256 3c85bf7ece3fb507…

MALICIOUS

PDF

80.7 KB Created: 2021-09-05 00:16:12 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 7d96bdbd683125ed03b985f5d3c5e95b SHA-1: ca2aca461adbf03c9a7293de7b86d3ef25ef6774 SHA-256: 3c85bf7ece3fb50703366478f3a67ac0710e1952983d7aa7a2b517e91dcfbd4c
156 Risk Score

Malware Insights

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

The PDF contains a large number of embedded URLs, many of which point to compromised websites or are part of link farms designed to obscure the final destination. The ML classifier and ClamAV detection strongly indicate malicious intent, likely phishing or malware delivery. The presence of compromised CMS upload links further supports this, suggesting the PDF is used to funnel traffic to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9955

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://goldnumber.info/userfiles/file/64704326331.pdf In PDF document text
    • http://budka39.ru/files/9214558603.pdfIn PDF document text
    • https://luxurytravel-show.com/wp-content/plugins/super-forms/uploads/php/files/e62625f84f75d529218890b3c7fc2da2/3493013185.pdfIn PDF document text
    • http://smflow.in/admin/uploads/file/38440332879.pdfIn PDF document text
    • http://ksklinika.ru/ckfinder/userfiles/files/wodawajupasew.pdfIn PDF document text
    • http://discoveryenglish.org/wp-content/plugins/formcraft/file-upload/server/content/files/1607f1ab896e74---81784441877.pdfIn PDF document text
    • http://www.alex-vasilkov.ru/images/wisdom/file/dajebo.pdfIn PDF document text
    • http://a-swiss.com/upload/userfiles/file/lutubixa.pdfIn PDF document text
    • https://linhngapt.vn/upload/files/49301065842.pdfIn PDF document text
    • http://ottotech.center/userfiles/file/dazoxogukizusumo.pdfIn PDF document text
    • https://roomart.uz/ckfinder/userfiles/files/21519413854.pdfIn PDF document text
    • http://ottuk-e.org/userData/board/file/45373596005.pdfIn PDF document text
    • http://amoy-art.com/Upload/file/32991873239.pdfIn PDF document text
    • http://www.vljainandco.com/userfiles/files/27732019495.pdfIn PDF document text
    • http://bobiniauto.com/userfiles/file/29188661780.pdfIn PDF document text
    • https://www.advids.co/wp-content/plugins/formcraft/file-upload/server/content/files/1608f1f07745b3---7550073464.pdfIn PDF document text
    • http://doubler-son-capital.com/photos/files/dubezavurebivozajodono.pdfIn PDF document text
    • http://smsalumni1971.com/apadmin/uploads/userfiles/files/nemunomegupuj.pdfIn PDF document text
    • https://shared401k.com/wp-content/plugins/super-forms/uploads/php/files/81e2b9ba8f811500d2a9d84353a55d27/gusewufu.pdfIn PDF document text
    • http://gayaarchi.com/userfiles/file/20210616004243.pdfIn PDF document text
    • http://aeskulap24h.com/wp-content/plugins/formcraft/file-upload/server/content/files/160daece473d9c---64428562507.pdfIn PDF document text
    • http://www.nuricomuvakfi.org/wp-content/plugins/super-forms/uploads/php/files/is3oaksp1u3m61tt8u6qaquar6/12811113396.pdfIn PDF document text
    • https://readxyz.com/wp-content/plugins/super-forms/uploads/php/files/0fc9cf8557d80db7b68381eb38fa3ac8/83438383850.pdfIn PDF document text
    • http://thanhnienxp.com/vietkiendo/upload/file/40897203560.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/3vuEKuznOb8/uplcv?utm_term=computer+applications+in+electrical+engineering+pdfPDF 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_off0000d5f5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD5F5 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000ee07.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEE07 17408 bytes
SHA-256: c791a4f084dd427b498e61e3cbf5e519bb140379d9a6c05a43d43a10cad30574
font_02_sfnt_off00011b4d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11B4D 11092 bytes
SHA-256: fa877cff1734f5e2d1fdcb7898d31359bf872504b731b841ef15660ea6df5c0d