Malicious PDF — malware analysis report

Static analysis result for SHA-256 52531f39e04664df…

MALICIOUS

PDF

89.7 KB Created: 2021-09-16 08:45:45 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: d5257949e2b7c0300a33204df4011faa SHA-1: 58464848bcb027031a1cc7406cbba91f160142e0 SHA-256: 52531f39e04664df81f75dc5beff5b9859d220b9ed3602d8bee1257ee2bae1a1
104 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript and numerous external URIs, many of which point to compromised websites or disposable hosting, suggesting a malicious intent to redirect users. The ML classifier strongly indicates maliciousness, and the presence of JavaScript points towards potential exploitation or further payload delivery. The document body is heavily obfuscated and unreadable.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9942

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 https://krisoc.ru/uplcv?utm_term=goodnight+mr+tom+pdf+download+free PDF link annotation
    • https://muzeumkonstancina.pl/attachments/file/kuduzog.pdfIn PDF document text
    • https://coaching-jk-academic.com/ckfinder/userfiles/files/lapinapokitoje.pdfIn PDF document text
    • http://bienbao.org/uploads/files/xozewukofudilebozog.pdfIn PDF document text
    • http://jgbt.us/pds/userfiles/files/12001407968.pdfIn PDF document text
    • http://eggtesting.com/admin/uploads/file/zibamamoxasim.pdfIn PDF document text
    • https://snabavto.com/wp-content/plugins/formcraft/file-upload/server/content/files/16132f4221a9a0---nasuzibesimededorutadi.pdfIn PDF document text
    • http://avtokapriz42.ru/userfiles/file/76596931836.pdfIn PDF document text
    • https://arichaindia.com/userfiles/file/84373266239.pdfIn PDF document text
    • http://www.msjcongregation.org/www/js/ckfinder/userfiles/files/34857936615.pdfIn PDF document text
    • http://elesi.eu/fichiers/files/75483699513.pdfIn PDF document text
    • http://www.miamiairportlimo.net/wp-content/plugins/formcraft/file-upload/server/content/files/161385c7a83ca7---61492158322.pdfIn PDF document text
    • http://thaimassagemodel.com/ckfinder/userfiles/files/48304375432.pdfIn PDF document text
    • http://pphu-joanna.pl/fckpliki/file/15575723346.pdfIn PDF document text
    • http://sb-78.ru/files/file/17772115907.pdfIn PDF document text
    • http://restokrat.info/userfiles/file/74714340825.pdfIn PDF document text
    • https://www.bakkersvlaanderen.be/resources/plugins/ckfinder/userfiles/0/files/boxasirisukizejaserom.pdfIn PDF document text
    • http://www.gonouvellezelande.com/files/larudipiragaxumogotu.pdfIn PDF document text
    • https://nstoplana.rs/ckfinder/userfiles/files/69357306415.pdfIn PDF document text
    • http://cdkuysuujk.handysociality.com/upload/files/40555638597.pdfIn PDF document text
    • http://donaldnathanlaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/bisosis.pdfIn PDF document text
    • https://home18.ru/wp-content/plugins/super-forms/uploads/php/files/dee75be8f8c230e48de3be1ae567a042/pojogu.pdfIn PDF document text
    • https://hankilfood.com/upfile/files/pajapuga.pdfIn PDF document text
    • http://elosc.com/upFile/file///ITX202109070205218620.pdfIn PDF document text
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#In PDF document text
    • http://purl.org/dc/elements/1.1/In PDF document text
    • http://ns.adobe.com/pdf/1.3/In PDF document text
    • http://ns.adobe.com/xap/1.0/In PDF document text
    • http://ns.adobe.com/xap/1.0/mm/In PDF document text
    • http://ns.adobe.com/xap/1.0/rights/In PDF document text
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000f691.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF691 19224 bytes
SHA-256: 9306f6da4564f97c439d508b6fb26730b0cbc835052b32182f2f270ba39bfdcb
font_01_sfnt_off00012882.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12882 10904 bytes
SHA-256: 98d523895a366b3d35e033bf0cd5eec850688a5dd6bac5318d7359b577235d64
font_02_sfnt_off00014160.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x14160 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1