Malicious PDF — malware analysis report

Static analysis result for SHA-256 55e9913c49a844f7…

MALICIOUS

PDF

88.1 KB Created: 2021-06-30 12:18:18 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 3981e6e20cf2c4a048dc7f4807f0fc84 SHA-1: 6dcb96c9f38be0d5936af135c04bf8cd0d61a0c2 SHA-256: 55e9913c49a844f7f963de2e938b136f293f5155ec5f2ab2f7291c7f2ec43d87
156 Risk Score

Malware Insights

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

This PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. The heuristics reveal it functions as a link farm, with numerous URLs pointing to compromised CMS upload directories. These links likely serve as lures for phishing or to distribute further malware. No scripts were extracted, but the structure suggests exploitation of PDF vulnerabilities or social engineering to trick users into clicking the embedded links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9961

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://adbetelparaguay.com/wp-content/plugins/super-forms/uploads/php/files/be19a8017f29d633d2cb9e27cae097e9/93385839952.pdf
    • https://rsun.pro/admin/ckfinder/userfiles/files/56081629903.pdf
    • https://m-astar.com/UserFiles/files/37249106845.pdf
    • https://www.geosuiteonline.de/wp-content/plugins/formcraft/file-upload/server/content/files/1606f50aa6b851---labawezevigusiwal.pdf
    • https://www.chinacimctrailer.com/wp-content/plugins/super-forms/uploads/php/files/fccca1e144a6201156359472b6f892f6/jokozomiribodu.pdf
    • https://www.jahnigterbraak.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160962f2bb6593---4628898174.pdf
    • https://sellerflows.com/wp-content/plugins/super-forms/uploads/php/files/fd703f9fd001eff9bcdcda2d9917bba9/xuxomevoxolulixiruvo.pdf
    • https://big-cash.de/wp-content/plugins/super-forms/uploads/php/files/1eqjve3l73rml8c74bjc4is1o6/rofuxisinukogetowo.pdf
    • https://sheenabusesandcoaches.com/userfiles/file/vexafodelidu.pdf
    • https://www.citysecurity.org.uk/wp-content/plugins/super-forms/uploads/php/files/p70q0vp8qqunp513hnesogr5r1/taredimava.pdf
    • http://uniondeautoescuelas.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b37a86599bf---lovuditiji.pdf
    • http://ttccid.com/userfiles/files/74798813958.pdf
    • http://amtusa.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b8b6d0aa839---98936331488.pdf
    • http://pulsrmedia.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609cd3953ec0e---kalanudovizolaj.pdf
    • http://congtrinhnhaviet.vn/upload/files/mosoxanefuditubovuxefe.pdf
    • http://www.optionassurance.ca/wp-content/plugins/formcraft/file-upload/server/content/files/16079e2201bbda---68220568412.pdf
    • http://erfolgsapp.de/wp-content/plugins/formcraft/file-upload/server/content/files/1607f4bc430414---wavamabowutijozagetox.pdf
    • http://www.reroofingbrisbaneqld.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/1606f36cf50a16---wuperizemuwuwasemavuverax.pdf
    • http://chinalabware.ru/d/files/89789115567.pdf
    • http://saxons99.com/clients/5/5f/5faa49e4155ddd0d4faf97b0d7aa3dde/File/59338642496.pdf
    • http://hellnocancershow.com/wp-content/plugins/formcraft/file-upload/server/content/files/160cecdc2b9db0---jokozidezovufepuzojez.pdf
    • http://yaqeen-eg.com/userfiles/file/17176806192.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/A3Ryygt5BCM/uplcv?utm_term=antiope+robin+wright
    • 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_off0000f5f2.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xF5F2 16792 bytes
font_01_sfnt_off00010e09.bin
4ca7ac93cf2d520d1333c5ec064146d9d2f217d586e6d522a73163120cc2f99a
pdf-font-stream PDF embedded font (sfnt) at offset 0x10E09 10364 bytes
font_02_sfnt_off00012537.bin
ec239c252d334ecc0b0c4c696169e8b2c8156b6e8ef274098d512e50d7650a9a
pdf-font-stream PDF embedded font (sfnt) at offset 0x12537 17764 bytes