Malicious PDF — malware analysis report

Static analysis result for SHA-256 4e1d9bbd2c086f21…

MALICIOUS

PDF

75.0 KB Created: 2021-09-01 10:26:27 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: b88880c48df825135ede6d311a980c43 SHA-1: ee60b879c2901bbbf025546ce6d09f0774a74bc1 SHA-256: 4e1d9bbd2c086f212feeab4618d94c1b03630122886cc93eb20ce73f9e4e26df
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was flagged by ClamAV as Pdf.Phishing.Trojan and by an ML classifier, indicating malicious intent. It contains numerous links to external websites, many hosted on compromised WordPress sites, suggesting a link farm designed to redirect users to malicious content or phishing pages. No scripts were extracted, but the presence of multiple PDF_SEO_DISPOSABLE_LINK_FARM and PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM heuristics strongly supports the link farm attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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://informerfitness.com/wp-content/plugins/super-forms/uploads/php/files/a21a2818c858aef16bfc5f871c588b80/24903116902.pdf
    • http://saharun.org/uploads/ckfinder/userfiles/files/muravisagogavifagofaz.pdf
    • http://cleannshieldflorida.com/wp-content/plugins/super-forms/uploads/php/files/a71677191a2c0d0d59df47bb0cbe3e5e/48489530531.pdf
    • https://csom.cz/wp-content/plugins/super-forms/uploads/php/files/0d4766b7d0e1f3322f929fd7037f30ad/wafojolozagef.pdf
    • https://www.alphaveneers.com/wp-content/plugins/super-forms/uploads/php/files/5a2150dd66bdd5ef4d3d99958d78ea53/80007411236.pdf
    • https://www.pennlighting.com/wp-content/plugins/super-forms/uploads/php/files/ce5aaa4c1c063c91991375f4da05831e/54233563864.pdf
    • https://nestsearch.in/admin/uploads/file/32229263794.pdf
    • http://richmore.kr/uploadfile/fckeditor/file/wosilikimitolagujido.pdf
    • http://temple.mo/userfiles/file/861063731.pdf
    • http://www.fliesen-brill.de/wp-content/plugins/formcraft/file-upload/server/content/files/160c253bd56b68---puxokavejaregog.pdf
    • http://hotelpenza58.ru/ckfinder/userfiles/files/nojufotefurufovuzij.pdf
    • http://ithaca1962.com/clients/41687/File/vedifirenizebopurawaxu.pdf
    • https://frontiersneurophotonics.org/wp-content/plugins/formcraft/file-upload/server/content/files/1/1608b0fd278b48---93637798282.pdf
    • https://duocvinhkim.com/userfiles/file/naboropiwokisud.pdf
    • http://caribsplash.org/wp-content/plugins/formcraft/file-upload/server/content/files/16085076526806---9190248581.pdf
    • http://hpworld.hu/data/pic/Image/file/95460920989.pdf
    • http://europeanprofservices.com/wp-content/plugins/formcraft/file-upload/server/content/files/160aabeb05246e---jubegazas.pdf
    • http://romanakladatelstvi.cz/userfiles/file/sirolu.pdf
    • https://vocembalo.ch/userfiles/file/49048674970.pdf
    • http://szguilong.com/userfiles/files/xivifimuxa.pdf
    • http://www.deep2001.com/images/library/File/sutifoxejojobap.pdf
    • https://www.rockfallco.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606cb88fcc89a---bidilususozenawuluk.pdf
    • https://udachi.co.th/wp-content/plugins/super-forms/uploads/php/files/gdba8ppnl07pt824dgs4ceh10r/novivonumusav.pdf
    • http://www.putnamtaxi.net/wp-content/plugins/formcraft/file-upload/server/content/files/1608a771c8a7a6---85441464278.pdf
    • https://ooobelkom.ru/ckfinder/userfiles/files/44826579643.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/BvfzZFkJO3s/uplcv?utm_term=ups+network+management+card+2+manual
    • 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_off0000bf5a.bin
6ca667d1570d366cf7c43f13477f0be52c29f85f7d6133624a04a470aa2af92a
pdf-font-stream PDF embedded font (sfnt) at offset 0xBF5A 11172 bytes
font_01_sfnt_off0000d972.bin
f9bc4c0edd44a2a9982db15d67e20f853d7dcec6703473a7b85eb1ffaa5a608b
pdf-font-stream PDF embedded font (sfnt) at offset 0xD972 17168 bytes
font_02_sfnt_off0001060d.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x1060D 16792 bytes