Malicious PDF — malware analysis report

Static analysis result for SHA-256 5caf67b81124e943…

MALICIOUS

PDF

80.0 KB Created: 2021-07-03 15:15:26 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 5c5a8608c6e36b6245a97eb225ec3979 SHA-1: 27516424682a778c932e369f25d6b555c013786f SHA-256: 5caf67b81124e943a5ad7884204bd4adf88fb676fb4dcbbbdada0ce48b153fb9
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF containing embedded JavaScript, which is a common technique for executing malicious code. It also exhibits characteristics of a link farm, with numerous URLs pointing to potentially compromised WordPress sites, suggesting an attempt to obscure the final malicious destination. The ClamAV detection and ML classifier strongly indicate malicious intent, likely for phishing or malware delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9968

Heuristics 7

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://joyfool.art/wp-content/plugins/super-forms/uploads/php/files/21559947588eb6d14d63520b3becf197/sevirijo.pdf
    • http://paintingservicesonline.ca/wp-content/plugins/formcraft/file-upload/server/content/files/160bac1f3ad1a0---83399338513.pdf
    • https://samowar.ch/upload/file/gofixumefi.pdf
    • http://ikuma-car.com/js/upload/files/51260154599.pdf
    • http://aliglobshop.com/userfiles/file/68698797251.pdf
    • http://www.appsolutely.sg/wp-content/plugins/formcraft/file-upload/server/content/files/1607054395309b---zazezites.pdf
    • http://www.tif.cn/wp-content/plugins/super-forms/uploads/php/files/kpl3jvmhh7ojks2fj4o7qtr7r6/xofijefeloxuninibu.pdf
    • https://www.bountyvacation.com/wp-content/plugins/formcraft/file-upload/server/content/files/16092ac5dcc9b0---15948140302.pdf
    • https://puertoestereo.com/wp-content/plugins/super-forms/uploads/php/files/58kmk4s5qe51vq1lrcqahaetnq/risozi.pdf
    • http://www.goataxiservice.com/wp-content/plugins/formcraft/file-upload/server/content/files/160850ac670323---8745285455.pdf
    • https://earplighting.com/wp-content/plugins/super-forms/uploads/php/files/a72fb7279c442408e80600ac861cff87/49951463339.pdf
    • http://viacaosaopedro.com/www/js/ckfinder/userfiles/files/68482736586.pdf
    • http://fitnessklub-impuls.pl/uploads/assets/file/keteg.pdf
    • http://ivepe-elearning.gr/assets/UserFiles/mainHome/file/benirufotujat.pdf
    • http://luckyassessoria.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160749f3a76851---9038463948.pdf
    • https://misionesmedellin2030.com/wp-content/plugins/super-forms/uploads/php/files/askj8qv32jhni9jvp5bnl8c3ea/pomodutirulifa.pdf
    • https://agsposure.org/wp-content/plugins/super-forms/uploads/php/files/8733f356b516e5afcf1176b7b0aedaf2/kuzadugojotobakumopigowir.pdf
    • https://www.heainc.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c6fffc72deb---gatovewejukapi.pdf
    • https://georgiamusicpartners.org/wp-content/plugins/super-forms/uploads/php/files/42bcad5d211648535fa2a714abfb730e/73704726825.pdf
    • http://luckyassessoria.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160763d887d070---65987470806.pdf
    • https://service-panev.com/userfiles/dokajomibibifir.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/Om9ozkHLxGw/uplcv?utm_term=weekly+schedule+on+excel
    • https://bxthirteen.wpengine.com/wp-content/plugins/super-forms/uploads/php/files/f09b9ee37a0c4d9a2e3ca405716b16fe/6971377066.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_off0000d7ae.bin
4124182137d5c5b8fee35222e558b24d55e27875b971dcc9771fd899a8afe040
pdf-font-stream PDF embedded font (sfnt) at offset 0xD7AE 16856 bytes
font_01_sfnt_off0001034a.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x1034A 16792 bytes
font_02_sfnt_off00011b61.bin
cc6624928ed015cf98fc1ba1b3ea9c1e739e5274276cf135827c22a6a6f96a42
pdf-font-stream PDF embedded font (sfnt) at offset 0x11B61 10416 bytes