Malicious PDF — malware analysis report

Static analysis result for SHA-256 a81795572b251d59…

MALICIOUS

PDF

82.4 KB Created: 2021-06-25 15:42:05 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: c8409af3cf70dd339e522cae4fe5d35b SHA-1: 1ab2c4a2d160140f0c55cf1450d1e03510aa571c SHA-256: a81795572b251d599d5c191b19d5362288437bb4da956f1d9c3508f0548fd6a4
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 the document functions as a link farm, directing users to multiple compromised WordPress upload directories. These links are likely intended to host further malicious content or phishing pages.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9992

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 http://windcampus.com/wp-content/plugins/formcraft/file-upload/server/content/files/16087e29f83da9---wakepivetuwuniremegaw.pdf
    • http://www.appsolutely.sg/wp-content/plugins/formcraft/file-upload/server/content/files/1607919b361bba---zemekixuvuduforokonoteru.pdf
    • https://northstarexecutivesearch.com/wp-content/plugins/super-forms/uploads/php/files/cf896285ed662732f6e7a4d2e29df335/norifo.pdf
    • http://acupunctuuryao.nl/ckfinder/userfiles/files/56954315449.pdf
    • http://bergfin.se/wp-content/plugins/formcraft/file-upload/server/content/files/16083953c6b6b3---panegadine.pdf
    • https://westcoastmovers.ca/wp-content/plugins/super-forms/uploads/php/files/br26qu6kk7iu5bp70dqc7nto0n/37878585305.pdf
    • http://www.champcaregivers.com/wp-content/plugins/formcraft/file-upload/server/content/files/160afa43e5738c---96487137361.pdf
    • https://slavica.ru/wp-content/plugins/super-forms/uploads/php/files/88ff425015d0e16f11b8316f01400404/larilolulonoredamubutilew.pdf
    • https://noks.cz/wp-content/plugins/formcraft/file-upload/server/content/files/1608cda44040d9---kizidudilatimumeniweko.pdf
    • http://thaoduocquyhiem.com/userfiles/image/file/22400077646.pdf
    • https://www.davidcosz.de/wp-content/plugins/super-forms/uploads/php/files/t35aln6a74rdddm26pnc76j2nc/12253408344.pdf
    • https://www.tessilgiada.it/wp-content/plugins/formcraft/file-upload/server/content/files/160b0832b0926e---rewafidagu.pdf
    • http://www.rec39.ru/wp-content/plugins/super-forms/uploads/php/files/b2dfc1c6ab1e82f7a3741e08b4b8fda3/29047885421.pdf
    • https://manuscripthandler.com/userfiles/file/58686137655.pdf
    • https://erdemlerkoleji.com/resimler/files/38248021.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/6naE_Nh8_CY/uplcv?utm_term=aluminum+reacts+with+oxygen+to+form+aluminum+oxide+balanced+equation
    • 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_off0000db5a.bin
129e4cf8da6a096a0f293b713ab44ba4f827e32be82d0dcc718a8c8679f4498e		 pdf-font-stream PDF embedded font (sfnt) at offset 0xDB5A 17552 bytes
font_01_sfnt_off0001096d.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1		 pdf-font-stream PDF embedded font (sfnt) at offset 0x1096D 16792 bytes
font_02_sfnt_off00012184.bin
7f39e6f061251fbf47b2eb9495e05ba7501bbff6edbd2fe8d8be2c8f4293c960		 pdf-font-stream PDF embedded font (sfnt) at offset 0x12184 11592 bytes

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