Malicious PDF — malware analysis report

Static analysis result for SHA-256 6839f30a185d98db…

MALICIOUS

PDF

107.8 KB Created: 2021-07-21 15:35:42 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: a983497da55f1e9026e7f7dbfad5c655 SHA-1: 17d0b64c88e8f65d5ea814ef94b115144f52aa15 SHA-256: 6839f30a185d98db816f17f2cb5d572a8881a69f260c7601d0c4db97dbe40457
156 Risk Score

Malware Insights

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

The PDF file contains numerous external links, many pointing to other PDF files hosted on compromised WordPress sites, indicating a link farm designed to distribute malicious content. The ClamAV detection and ML classifier strongly suggest this PDF is malicious, likely serving as a lure for phishing or malware delivery. No scripts were extracted, but the structure and URL patterns are indicative of a malicious campaign.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9898

Heuristics 6

  • 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.
  • 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://spherule.org/wp-content/plugins/super-forms/uploads/php/files/545b79e383c337a2ee7cc46cc20d4023/fepawanizokusa.pdf
    • http://mgmkt.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1606f4a32bb187---jotimajunugovudefu.pdf
    • http://scbczy.cn/up_files/file/20210627_072905.pdf
    • http://bhs-class1957.com/clients/35434/File/dapiven.pdf
    • https://ltgtrends.com/wp-content/plugins/super-forms/uploads/php/files/14dcfee5580848f0a73d13149ef13b46/49357389482.pdf
    • https://slavica.ru/wp-content/plugins/super-forms/uploads/php/files/dd5cdc295436d67426cf57d30e323730/50311113430.pdf
    • https://www.drserapkagan.com/wp-content/plugins/super-forms/uploads/php/files/p2ediqj1a5l15i461dj2shn5n1/29737389091.pdf
    • https://seataclightingalaska.com/wp-content/plugins/super-forms/uploads/php/files/a9899c7e8295546333c08654b4f02835/povewomifejumijeku.pdf
    • http://accessiblevehicleservices.com/userfiles/file/zulafonadazizilawimab.pdf
    • https://sieuviet.net/webroot/img/files/xorebujujekulijesufolijej.pdf
    • https://www.rydalmereprestige.com.au/wp-content/plugins/super-forms/uploads/php/files/pc453mc7qf5c1vh5tifl5fncto/veregezazula.pdf
    • http://rebizplus.com/userfiles/file/61413035837.pdf
    • https://ladychief.com/wp-content/plugins/super-forms/uploads/php/files/b1b5318131d0b0ea77060ff85b7c3cbd/fololegebasadazuxav.pdf
    • http://aeskulap24h.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b46a0acf851---rimaso.pdf
    • https://samowar.ch/upload/file/xetewibijenajilemivedejam.pdf
    • https://www.sgestrecho.es/wp-content/plugins/formcraft/file-upload/server/content/files/160703e946c872---ripas.pdf
    • http://pivotal-technologies.com/userfiles/file/58367411466.pdf
    • https://swimproject.eu/wp-content/plugins/super-forms/uploads/php/files/7543c3bdd89056755ff0aabd908277d2/kalalegetawefeloza.pdf
    • http://audiomaster.se/wp-content/plugins/formcraft/file-upload/server/content/files/160861763ecd04---3177358122.pdf
    • http://ipvoicenj.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607ba0b2c1fc5---39103195905.pdf
    • https://cheesykeju.com/contents//files/82299964657.pdf
    • http://novussiteyonetimi.com/uploads/file/setalapibusovegunigaw.pdf
    • https://bodegoncriollo.com/userfiles/file/farelotepatajovore.pdf
    • http://sportingclubalbinia.eu/userfiles/files/zapivomixikaxurenerelovu.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/YTWXjIUwRh0/uplcv?utm_term=how+do+you+pronounce+chinese+currency
    • 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 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00010672.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x10672 16792 bytes
font_01_sfnt_off00011e89.bin
492d6de7f7a94e65aa2421a8836c6056efd6925482cdc4151f91f4062df42145
pdf-font-stream PDF embedded font (sfnt) at offset 0x11E89 10596 bytes
font_02_sfnt_off000136a9.bin
2b5ab73e5a55f6979b58dec31744d3445b7c9fc8dc1a89ad2e70492667de0162
pdf-font-stream PDF embedded font (sfnt) at offset 0x136A9 21880 bytes
font_03_sfnt_off00016c82.bin
e3165f066e02ff6dbc4cf92c8a1dd9c4e2a6442fba4ce08da1f98ade3f1eeee1
pdf-font-stream PDF embedded font (sfnt) at offset 0x16C82 17452 bytes