Malicious PDF — malware analysis report

Static analysis result for SHA-256 31aef6fc8ff5162b…

MALICIOUS

PDF

82.2 KB Created: 2021-08-30 10:56:39 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 8371579e124aedd6c0e84fe55642d818 SHA-1: 22ad8fdee512331785ce2f55a8971c4c6608298b SHA-256: 31aef6fc8ff5162bc43e8ff8b6ef3f3c4d9a66c8fd84583b54e96bc4dd3043cf
96 Risk Score

Malware Insights

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

The PDF file contains a link farm pointing to numerous distinct hosts, many of which are compromised WordPress upload storage locations. The ML classifier strongly indicates maliciousness, and the structure suggests an attempt to manipulate search engine results or distribute further malicious content. No scripts were extracted, and the document body was unreadable, limiting the ability to determine the exact payload or intent beyond link distribution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9991

Heuristics 5

  • 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://sinarwaja.com/account/files/koxaxigijuxov.pdf
    • http://www.trimbleexpress.sk/wp-content/plugins/formcraft/file-upload/server/content/files/1607337f9b4e97---pekomamifekazaweb.pdf
    • http://systemsbiology.at/uploads/assets/file/dareduzifuwonetumitikumi.pdf
    • https://rebates.forex/wp-content/plugins/super-forms/uploads/php/files/4ipbab26k705nlt6127a9ne6b3/5408327386.pdf
    • http://ecohost.ru/pics/images/file/zisopawumajuvemob.pdf
    • http://drinkandshrink.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/160c7584ecf222---zufozuzoxopupoj.pdf
    • https://www.lashharmony.co.uk/wp-content/plugins/super-forms/uploads/php/files/0aqmu8ol7iio6bdl4auupd7qih/buxuzilamawowojowusamanip.pdf
    • http://wahluenfty.com/userfiles/sepofitumigevuri.pdf
    • http://www.primalegal.eu/wp-content/plugins/super-forms/uploads/php/files/ial5fcnh9e034jac7brlaqij81/97535170816.pdf
    • http://holzweiss.at/57150999335.pdf
    • http://aaexpansionjoint.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a015cba28e5---lidijexejusiwizawoborazi.pdf
    • http://maasmartcity.com/userfiles/file/zorozofexa.pdf
    • https://htfcompact.com/wp-content/plugins/super-forms/uploads/php/files/df62400e7da9ea49be30c6848c72c5e6/vigadisavub.pdf
    • https://barcelonamedicalcenter.com/files/galeria/files/40765814739.pdf
    • https://solener.info/ckfinder/userfiles/files/48786771580.pdf
    • https://neoville.ru/wp-content/plugins/super-forms/uploads/php/files/329ce546255ac00206cf78380cd3a572/76322808833.pdf
    • http://s8radziejowice-paszkow.pl/userfiles/file/58488538985.pdf
    • http://ip-golubev.ru/ckfinder/userfiles/files/77474197410.pdf
    • http://pauseforserenity.com/clients/1/10/1002a5d8b3740fc7390aa1937d1ec3ed/File/50561291766.pdf
    • https://valerart.com/ckfinder/userfiles/files/patojimega.pdf
    • http://clearlakesd.org/wp-content/plugins/formcraft/file-upload/server/content/files/16112c41b05522---dopus.pdf
    • https://primer-spb.ru/files/files/lopejojarawobokego.pdf
    • https://www.mysmilestudios.com/wp-content/plugins/super-forms/uploads/php/files/99bbe3d70ebab20d35db4f64f565b443/58251188709.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/YTWXjIUwRh0/uplcv?utm_term=child+audition+for+tv+serial+2020
    • 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_off0000dbcf.bin
d684d583d2b3304a1a4c0655ea16daf752bf6ea57c476cf0721bf3aa8c06894d
pdf-font-stream PDF embedded font (sfnt) at offset 0xDBCF 10888 bytes
font_01_sfnt_off0000f505.bin
9fb40b89694063a9df86f309f42724ff613443f05f1315826076ff7a7e51c186
pdf-font-stream PDF embedded font (sfnt) at offset 0xF505 17984 bytes
font_02_sfnt_off000123ae.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x123AE 16792 bytes