Malicious PDF — malware analysis report

Static analysis result for SHA-256 8191ab13c1551cc2…

MALICIOUS

PDF

88.9 KB Created: 2021-06-28 20:51:03 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 4bb9f91caa7ecd975e4956e261167398 SHA-1: bb5aa0d57e339ca47b04c605f6e5f201e9e992ab SHA-256: 8191ab13c1551cc228386db6e2ed84c399e8a8e366d13dd69dbaed51f8a280de
156 Risk Score

Malware Insights

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

The PDF file was identified as malicious by ML classifiers and ClamAV. It contains a link farm with numerous URLs pointing to compromised CMS uploads and disposable hosting, suggesting an attempt to distribute malicious content or phish users. The document body is heavily obfuscated and does not provide direct textual clues, but the heuristic firings strongly indicate a malicious link distribution scheme.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9991

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://md-servicios.com/userfiles/file/55626456763.pdf
    • https://2greenchicks.com/wp-content/plugins/super-forms/uploads/php/files/300b8572a53beb74e0a7c41098e90862/rebixuzubeje.pdf
    • http://ecohouse-lab.com/userfiles/file/50312933783.pdf
    • http://cageart.ca/wp-content/plugins/formcraft/file-upload/server/content/files/160789fa3c276f---bubibugetutekapagajow.pdf
    • http://msci.com.ng/wp-content/plugins/formcraft/file-upload/server/content/files/1606f13510e956---ruvabalajeke.pdf
    • http://stopasbestos.ca/wp-content/plugins/formcraft/file-upload/server/content/files/1608fbec2f1413---narewaketaro.pdf
    • https://lcd96.ru/wp-content/plugins/super-forms/uploads/php/files/81c8fb7ad59e7de2373037020fd3efcd/51795723501.pdf
    • http://conroeclassof72.com/clients/d/de/de0acc14889d5d69ce6a2e221f3e79cd/File/serototibewora.pdf
    • http://erkerlaender.de/wp-content/plugins/formcraft/file-upload/server/content/files/160a4cf379751e---33241467898.pdf
    • http://imreelectric.sk/uploads/file/sotefumaloxusomabesef.pdf
    • https://tezerwatch.com/file/upload/files/06-18-03-25-12-44.pdf
    • https://www.dentaltaxpros.com/wp-content/plugins/super-forms/uploads/php/files/65cee08ebbe8a5360ffc4b5a816e9539/1173257533.pdf
    • https://victory-agency.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609af7e4ca80c---9935624637.pdf
    • https://signaturetowerpune.com/wp-content/plugins/super-forms/uploads/php/files/vjbv3bo0um87uho7uc8vf2tf12/nadozazifarasovagowefav.pdf
    • http://seamacros.com/upload/file/biberos.pdf
    • https://www.cocochan.com.pk/wp-content/plugins/super-forms/uploads/php/files/e6bfc88651ff767b32ffe597508c288f/97328105269.pdf
    • http://edwardnugent.com/userfiles/files/xorunek.pdf
    • http://schmetterlingsgaerten.de/file/48529170179.pdf
    • https://stewsites.com/wp-content/plugins/super-forms/uploads/php/files/6f12b38115e88c57ca57cbafdd75171f/61714946842.pdf
    • https://xistenze.com/files/files/fusozafukeg.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/YTWXjIUwRh0/uplcv?utm_term=basic+elements+of+real+analysis
    • 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_off0000f900.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xF900 16792 bytes
font_01_sfnt_off00011112.bin
4e120960131d370c925928fd21ae5f2514e0c9d0615e64d897c79e332eee7e95
pdf-font-stream PDF embedded font (sfnt) at offset 0x11112 17196 bytes
font_02_sfnt_off00013e12.bin
73958aba73f57dc627fe1c6c542245b0d54cbfd439aed04e07254d152b7f1efc
pdf-font-stream PDF embedded font (sfnt) at offset 0x13E12 10664 bytes