Malicious PDF — malware analysis report

Static analysis result for SHA-256 91c1774eb2c019df…

MALICIOUS

PDF

73.7 KB Created: 2021-09-04 06:51:39 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: 183f8461a9ae8e62e6e67fa2459e638d SHA-1: 084c61724647a2f7bcc94934a80b2df17a8f527a SHA-256: 91c1774eb2c019df3259de48c9f6c6aeea2e79ba53b037ece2c0001acd230774
136 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution T1059.007 JavaScript

The PDF document employs a social-engineering tactic by presenting a lure to install a browser extension or update, a common method for distributing malware or stealing credentials. The numerous embedded URLs, many pointing to compromised CMS uploads, suggest a distribution network for malicious payloads. While no scripts were directly extracted, the ML classifier strongly indicates malicious intent, likely involving exploitation or further payload delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9963

Heuristics 6

  • Browser extension / update installation lure high SE_BROWSER_INSTALL_LURE
    Document tells the user to install a browser extension, plugin, viewer, or browser update to view content — a common social-engineering path for credential theft and malware installation
  • 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://oniceh.ru/uplcv?utm_term=hemolisis+sel+darah+merah+pdf PDF link annotation
    • http://proxkimya.com/resimler/files/kajemowadabejin.pdfIn PDF document text
    • http://ithaca1966.com/clients/8/85/85e9e0a76fddb83d7689cebc6ab07fae/File/6202072309.pdfIn PDF document text
    • https://bykevin.com/wp-content/plugins/super-forms/uploads/php/files/b5fb0cf99369262f967de31cf50e6509/8082844393.pdfIn PDF document text
    • https://www.sudburyhighspeedinternet.ca/wp-content/plugins/super-forms/uploads/php/files/9fe7b2484b838887bc1b76b8125d2a91/wopakomuji.pdfIn PDF document text
    • https://razvozka24.ru/wp-content/plugins/super-forms/uploads/php/files/8ecae21af91f750bf1070f375e62ef38/85804310669.pdfIn PDF document text
    • http://smlstripedbass.com/home/rock/public_html/ckfinder/userfiles/files/desiradivesikosikiras.pdfIn PDF document text
    • https://aeternoplanning.com/ckfinder/userfiles/files/xodilomaj.pdfIn PDF document text
    • https://bykevin.com/wp-content/plugins/super-forms/uploads/php/files/f7c3c1b3b8466fc5d1dc7f763616033e/kimobepejidegezerasi.pdfIn PDF document text
    • https://aquatim.ro/uploads/files/bifipiwelajaro.pdfIn PDF document text
    • https://hacunamatata.ru/wp-content/plugins/super-forms/uploads/php/files/cc2ba4a664777fa6ec64686aad7087e2/84365758030.pdfIn PDF document text
    • http://www.highlandmetals.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/160a9f7b0f3898---zelelaliguvad.pdfIn PDF document text
    • https://snabavto.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b4004f98c2e---42511241205.pdfIn PDF document text
    • http://wang023spa.com/userfiles/202108file/2021082804464270554.pdfIn PDF document text
    • https://www.vibrationmonitoring.asia/wp-content/plugins/formcraft/file-upload/server/content/files/160beb52ec75ae---82684966967.pdfIn PDF document text
    • https://greenfuturevietnam.com/Upload/files/kifibaziro.pdfIn PDF document text
    • http://chagatea.ru/wp-content/plugins/super-forms/uploads/php/files/9c0d1df294b85a8e50598b83defae55e/vubowuzigasuzidijini.pdfIn PDF document text
    • https://kenadong.com/contents//files/xokodabetone.pdfIn PDF document text
    • http://hong-tour.com/FileData/ckfinder/files/20210626_E5E06BFE7465E986.pdfIn PDF document text
    • http://wami.cc/data/files/zabaluvitiduganonoxe.pdfIn PDF document text
    • http://makinsushi.com/uploads/files/3560335457.pdfIn PDF document text
    • http://www.firstpages.eu/app/webroot/files/userfiles/files/47462380653.pdfIn PDF document text
    • http://metamorfoza-krosno.pl/userfiles/file/65473236693.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_off0000bd06.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBD06 10552 bytes
SHA-256: 5212fed2f76f4f80b243081f1bfdbd479a138413671266e743315cf06a1bac3a
font_01_sfnt_off0000d4fa.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD4FA 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000ed0c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xED0C 17052 bytes
SHA-256: d0328655c70d7db54fe06ef562ea95697c6e39356e970b63aec58c2c6c947aea