Malicious PDF — malware analysis report

Static analysis result for SHA-256 81cedacb54072a4e…

MALICIOUS

PDF

77.0 KB Created: 2021-09-17 16:43:24 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: f982e62a1db94b736e2b61969051d65b SHA-1: 83341a6de3bc56119f6130d61aa76d9e08bc8c51 SHA-256: 81cedacb54072a4e359b0d5d3a8dad40c694d680601e86f5b3bf850f0a358d0d
156 Risk Score

Malware Insights

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

The PDF was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, with numerous embedded URLs pointing to potentially compromised or disposable hosting sites. The primary purpose appears to be directing users to external malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9943

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://e68momo.com/shopadmin/upload/files/34298581149.pdf In PDF document text
    • http://hani-bee.com/userfiles/files/78812411519.pdfIn PDF document text
    • https://gujaratisamajparis.org/upload/files/98249026171.pdfIn PDF document text
    • https://www.leadercaravans.com.au/application/third_party/ckfinder/userfiles/files/zeloza.pdfIn PDF document text
    • http://skyrybupaslaugos.lt/uploads/files/97704924115.pdfIn PDF document text
    • http://kondicionery-dzerzhinskij.ru/upload_picture/file/woxedepixutudanunevosebu.pdfIn PDF document text
    • http://magdrywall.com/project-new/christianbook/upload_images/file/93896323488.pdfIn PDF document text
    • http://www.acefence.com/wp-content/plugins/formcraft/file-upload/server/content/files/16135da19b3834---30362254055.pdfIn PDF document text
    • https://konzolstudio.ro/uploaded_files/file/wurufamevetuwobes.pdfIn PDF document text
    • http://bogaarchitetti.it/userfiles/files/kafipumezunusanikuxoka.pdfIn PDF document text
    • http://biznesfishki.ru/files/userfiles/files/75147049215.pdfIn PDF document text
    • http://gomsuhoangminh.com/app/webroot/uploads/files/70849735791.pdfIn PDF document text
    • http://usairsprings.com/userfiles/file/46276932555.pdfIn PDF document text
    • https://istanbulbalbir.com/upload/ckfinder/files/40012550579.pdfIn PDF document text
    • http://gyarmatilovastorna.hu/userfiles/file/gikevesumexuti.pdfIn PDF document text
    • http://kramnyca.info/img/upload/editor/file/domofezaso.pdfIn PDF document text
    • http://alvasari.com/wp-content/plugins/formcraft/file-upload/server/content/files/161318e2d757d4---18843724088.pdfIn PDF document text
    • http://volareinmongolfiera.it/userfiles/files/tefov.pdfIn PDF document text
    • http://tostonet.cl/ckfinder/userfiles/files/zizixire.pdfIn PDF document text
    • http://lexen.ca/userfiles/files/fafugorerodapinudeve.pdfIn PDF document text
    • http://gillsandgeckos.com/userfiles/file/81837481708.pdfIn PDF document text
    • http://nokianhakkablue.ru/ckfinder/userfiles/files/65534572300.pdfIn PDF document text
    • https://mobspace.xyz/web/img/podborky/files/68680784048.pdfIn PDF document text
    • https://aldea.work/wp-content/plugins/super-forms/uploads/php/files/dbf44d235e2d0669562cfd9e31d77dfb/zedib.pdfIn PDF document text
    • https://heart-calligraphy.com/uploads/files/202109140446292106.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/DOqCt-cVA4I/uplcv?utm_term=sports+add+on+for+firestickPDF 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_off0000c7b3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC7B3 18124 bytes
SHA-256: 0f5ded2008e9f21bfce96b2d8dc64d45dacd67e07349abef023b47107c2147b0
font_01_sfnt_off0000f5d1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF5D1 10736 bytes
SHA-256: 57e525d412edc4401df9c1ae030b8b72b1367898f6e909fb86163867d2c518cb
font_02_sfnt_off00010e9b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10E9B 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1