Malicious PDF — malware analysis report

Static analysis result for SHA-256 8b11da778d28ad78…

MALICIOUS

PDF

84.7 KB Created: 2021-07-02 08:08:07 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: f505ab30d6dcfba118edf9a31253ba8d SHA-1: fb71ec87fe1231d405a02e8f0595d6ca27fe5be0 SHA-256: 8b11da778d28ad7837d66bba7234df285783265fd124a4cb7eddd79e883b7f74
104 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains an embedded JavaScript stream and numerous URLs pointing to compromised CMS uploads, forming a link farm. This suggests the document is designed to lure users into clicking these links, which likely lead to malicious content or phishing sites. The ML classifier strongly supports the malicious verdict.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9956

Heuristics 6

  • 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 http://www.platformliften.info/wp-content/plugins/formcraft/file-upload/server/content/files/1609f55ad7b466---fekusuturufuna.pdf
    • https://sk-developers.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609fa8f77db29---mikepejavabat.pdf
    • http://zs-oilfieldequip.ru/d/files/pivogipogobizumibutamemop.pdf
    • http://hoangle.vn/uploads/userfiles/file/javalesimexitikasubutigep.pdf
    • https://pinotcar.com/wp-content/plugins/super-forms/uploads/php/files/7c39c984aa2b6892cc95c8177ae704ff/35425167902.pdf
    • https://veritiesinstitute.com/wp-content/plugins/super-forms/uploads/php/files/f79a2393e9c9e21b2f158a9186edcb51/82547767532.pdf
    • https://binhruamuinanobac.com/wp-content/plugins/super-forms/uploads/php/files/67rdfvbol4bdd1qcch8uor1jeu/37070117392.pdf
    • http://centrumbiznesurawicz.pl/userfiles/file/nijozakajaluwupujo.pdf
    • https://jgmurphy.com/wp-content/plugins/super-forms/uploads/php/files/8a89aaf5187837c2a8b58f558c6849d8/67828887293.pdf
    • https://www.kiteschule-eckernfoerde.de/wp-content/plugins/formcraft/file-upload/server/content/files/160d2ec291591f---lililuwawabagilabajogodar.pdf
    • http://goodwill.as/userfiles/file/77720372027.pdf
    • https://usdcp.jp/user_data/userfiles/files/vilujepibibit.pdf
    • https://auto826.com/uploads/files/redapesamorivexos.pdf
    • https://englewoodgrassfarm.com/wp-content/plugins/super-forms/uploads/php/files/449b2f4b1a684c717e076cb243da0d01/gixukisazemakifefid.pdf
    • http://askort.pl/Upload/file/53856480049.pdf
    • http://rymwid-training.com/userfiles/file/bodisujigavajotojajibew.pdf
    • https://webgirls-studio.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607eefa249aa0---nagafevevusogari.pdf
    • https://www.lesson-online.org/wp-content/plugins/super-forms/uploads/php/files/a74i7v5to36t5c46iemi4o8sq2/11185660905.pdf
    • https://www.pferde-fuer-unsere-kinder.de/wp-content/plugins/formcraft/file-upload/server/content/files/16077e1ef96201---ziwanetuxipijuregun.pdf
    • http://www.chicagoalphas.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607700792d5c3---81572256001.pdf
    • https://gyandeepjkss.org/userfiles/file/13000138781.pdf
    • https://noble-program.site/js/ckfinder/userfiles/files/37041106144.pdf
    • https://bazab.ru/ckfinder/userfiles/files/5003492313.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/Om9ozkHLxGw/uplcv?utm_term=clash+of+clans+builder+base+layout+level+6
    • 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_off0000e7e0.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xE7E0 16792 bytes
font_01_sfnt_off0000fff7.bin
1bb50b6cb3e801e466793a0e19ddf819640e24703e4b208d7766d5a061fb7d35
pdf-font-stream PDF embedded font (sfnt) at offset 0xFFF7 11192 bytes
font_02_sfnt_off00011a28.bin
9a9130c58c9bc18c5f72d34491908d533356bd40d56881fe74baf7586357274d
pdf-font-stream PDF embedded font (sfnt) at offset 0x11A28 16664 bytes