Malicious PDF — malware analysis report

Static analysis result for SHA-256 c85ec0ca2779f111…

MALICIOUS

PDF

89.4 KB Created: 2021-06-30 08:23:06 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 3c4d10ad0cf5e56832b8faff2a7c281d SHA-1: 9167e29093c757dbfbb3e1b098d494b15940ac75 SHA-256: c85ec0ca2779f111f7798740b34d8c5b44a3cee8f6f60ddaf68f4e5eb811f8ef
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF contains a large number of links, many pointing to compromised WordPress sites, indicating a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely phishing or malware distribution through these links. The document body is unreadable, but the heuristic firings clearly point to a link-based attack.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9924

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://www.bouwenaaneensterkwerkgeversmerk.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1606f3ccd19a38---91710306275.pdf
    • https://inchiriereelicopterromania.ro/wp-content/plugins/formcraft/file-upload/server/content/files/160ba60e6e2e85---25571617434.pdf
    • https://computerzone.pk/file/zilosutenutega.pdf
    • https://carthink.org/wp-content/plugins/formcraft/file-upload/server/content/files/16098bfe75154f---sixixelivenen.pdf
    • https://www.ibyservice.com/wp-content/plugins/super-forms/uploads/php/files/bb023f013d7c211dd41dc9d9d112a63c/dupogukepisuveju.pdf
    • http://www.makattakasinti.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606d1d6427483---barevazupipexuloke.pdf
    • http://wksystems.net/HotelEstimator/userfiles/file/79446392655.pdf
    • https://www.cukoyem.com.tr/wp-content/plugins/super-forms/uploads/php/files/umm79pdsejatk2r8vlrjer6523/10047610339.pdf
    • http://xn--80ackbssfuieecff0e8c.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/jdn2dvm1bj2060epqhdod1q021/gexovarelikozajefemepuboz.pdf
    • https://controlcert.se/wp-content/plugins/formcraft/file-upload/server/content/files/16079b97eb6c0d---41987694282.pdf
    • https://alutat.com/data/file/28760413505.pdf
    • http://www.mkkdigital.pt/wp-content/plugins/formcraft/file-upload/server/content/files/16083f86fe950a---guxuxo.pdf
    • https://nguoixunghekiev.vn/userfiles/file/4751813629.pdf
    • http://thefutureofgolf.eu/wp-content/plugins/formcraft/file-upload/server/content/files/1609beb5b56bc8---fudinuzexolukoxelupezetig.pdf
    • https://eternalbliss.net/file/78665148805.pdf
    • https://eliteswimmingpoolsinc.com/wp-content/plugins/super-forms/uploads/php/files/b2qiq8sn0toonejcpltlvcjmo1/98935720305.pdf
    • http://axwelindia.com/uploads/pakakoxituropedif.pdf
    • http://usmleworkout.com/files/file/sulafafi.pdf
    • http://alliance-ltd.com/userfiles/5954095646.pdf
    • http://claudiodauelsberg.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160872823b137d---26920368447.pdf
    • http://www.publicitymailing.ie/wp-content/plugins/formcraft/file-upload/server/content/files/16097ab4da7e37---gaginarakujuwuko.pdf
    • https://hcs1000.org/wp-content/plugins/super-forms/uploads/php/files/a80c5f3fe9e47f2843c1f2aac3ae3bc5/laretojudamive.pdf
    • http://spc1991.com/ckfinder/userfiles/files/5927136223.pdf
    • http://duquenne-moteurs.fr/webroot/upload/files/92480235440.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/fzgW7-mxBc0/uplcv?utm_term=gl+manhwa+recommendations
    • 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_off0000ed1e.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xED1E 16792 bytes
font_01_sfnt_off0001052b.bin
9a16aaa2be92819fdff214d3cd7f4659f30d6e610dee2ec1f2840578db379035
pdf-font-stream PDF embedded font (sfnt) at offset 0x1052B 2528 bytes
font_02_sfnt_off00011017.bin
27314163821eed820eb2e8005e90e82469607efcd0839826d09eda5024f49464
pdf-font-stream PDF embedded font (sfnt) at offset 0x11017 10760 bytes
font_03_sfnt_off000128a9.bin
93201baa82eefd7e9326f168e42985b72540c9a2a5fd19de8ac33f9df66e8fe2
pdf-font-stream PDF embedded font (sfnt) at offset 0x128A9 17812 bytes