Malicious PDF — malware analysis report

Static analysis result for SHA-256 7ec6598718667f4c…

MALICIOUS

PDF

89.4 KB Created: 2021-09-05 14:45:16 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: c7d1b945fdd69041f54b3586078762cc SHA-1: 64ea6d3183151217434c4096a6edd7f657f8e5cb SHA-256: 7ec6598718667f4c4ef639d23cd50666fcf6598307f2556e91fe5e71699d733b
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is identified as a malicious PDF by multiple heuristics and a machine learning classifier. It contains numerous external URLs, many of which are hosted on compromised CMS uploads or disposable domains, suggesting a link farm designed to redirect users. The presence of PDF_SEO_DISPOSABLE_LINK_FARM and PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM heuristics indicates a tactic to obscure the true destination or leverage compromised infrastructure. While no scripts were explicitly extracted, the PDF structure and URL patterns are consistent with phishing or malware distribution campaigns.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9948

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://synerhu.ru/uplcv?utm_term=marcus+aurelius+book+pdf
    • http://korvet-sp.ru/userfiles/file/vobibebowexesoz.pdf
    • http://www.startservis.sk/novy/ckfinder/userfiles/files/lasufeluvovuwebi.pdf
    • http://all-pass.com/folder/editor/file/15704418116.pdf
    • http://www.movingintofreedom.com/wp-content/plugins/formcraft/file-upload/server/content/files/16074884ba90da---16099403000.pdf
    • http://lyzebrno.cz/userfiles/file/78060360966.pdf
    • https://functionalmovement.gr/wp-content/plugins/super-forms/uploads/php/files/191d59b14354cf616ca131b48a594569/mibilol.pdf
    • http://novena99.com/uploads/files/202109030452072134.pdf
    • http://bmhs1964.com/clients/a/ae/ae3b7fe25fc1fd458a9bccd7578bee9c/File/zakukiridelimipomujakano.pdf
    • http://ajtoablakcentrum.com/_user/file/tuwuvofuwotal.pdf
    • https://jaukiaplinka.lt/ckfinder/userfiles/files/belubizex.pdf
    • http://lbs.ac.at/wp-content/plugins/super-forms/uploads/php/files/vs05voqrddpm814cpvt8ujpnd8/kalunejopamexuxo.pdf
    • https://chiataiec.com/userfiles/Proj_Name//files/pipofafogoreri.pdf
    • https://frasertechno.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bd4220dcc9d---80639080525.pdf
    • https://www.sudburyhighspeedinternet.ca/wp-content/plugins/super-forms/uploads/php/files/fc42d831552e0f6ce400fab6dc340f74/gamabatademofinoz.pdf
    • http://automotiveenergy.cz/userfiles/file/werusejukiwozuxivi.pdf
    • https://www.beachesbrewing.com/wp-content/plugins/super-forms/uploads/php/files/153fbeceb8a67a9558d8bac46fcc9288/monebifomugos.pdf
    • https://tcufroghouses.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bcd1aa8d1f3---95182848446.pdf
    • http://haisushitogo.com/uploads/files/51598671986.pdf
    • http://munsusa.org/userfiles/file/20210605105423.pdf
    • https://webtraffic.ch/wp-content/plugins/super-forms/uploads/php/files/gvmmfk5aotehm30k2k7tp04pg0/witevekesuxumifoluv.pdf
    • https://yourtuscanyguide.com/wp-content/plugins/super-forms/uploads/php/files/eu9brkc6gpimkgup30sa2fnt63/15051545665.pdf
    • https://acryl-bg.com/userfiles/file/gopufajakiveve.pdf
    • http://www.thediethub.in/wp-content/plugins/formcraft/file-upload/server/content/files/160ac239634ded---18995270588.pdf
    • 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_off0000fa69.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xFA69 16792 bytes
font_01_sfnt_off0001127b.bin
84a9bda3f992bb036ac25672ca79e493d7bb206d55da2c0072a62227c24eb670
pdf-font-stream PDF embedded font (sfnt) at offset 0x1127B 17444 bytes
font_02_sfnt_off00013fdc.bin
bf010bd9d8bbb80b76736a3dd30103b78ba75519269021dd5e1d6b23e345e659
pdf-font-stream PDF embedded font (sfnt) at offset 0x13FDC 10736 bytes