Malicious PDF — malware analysis report

Static analysis result for SHA-256 f8a86fe3781bdc4e…

MALICIOUS

PDF

74.6 KB Created: 2021-06-25 12:12:47 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 83d480d92e7b5efe6fa4716991a05150 SHA-1: f14843c8d890c9b61d6c248976b7e6a974cd2d39 SHA-256: f8a86fe3781bdc4ea0586efa9eddb4c726165a836c7f70640caaa95625d99827
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It contains numerous links to external websites, many hosted on compromised CMS platforms, suggesting it functions as a link farm to distribute further malicious content or phishing lures. No scripts were extracted, but the PDF structure and URL patterns are consistent with phishing or malware distribution campaigns.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9994

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://stewsites.com/wp-content/plugins/super-forms/uploads/php/files/ad561bbb4b8edf925604e245024b62cf/88874932804.pdf
    • https://www.auditek.fr/wp-content/plugins/formcraft/file-upload/server/content/files/1607b167edb272---fimerobejipeg.pdf
    • http://hellnocancershow.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608444218a972---jonodirudorijokej.pdf
    • https://minutesnap.com/wp-content/plugins/super-forms/uploads/php/files/0db5fc02cf75e14aa55be8e46e1ebc16/vafefas.pdf
    • http://redwoodpwr.com/wp-content/plugins/super-forms/uploads/php/files/dl9mo63obav6steriai4p460p3/wagibubanagiwodovasiri.pdf
    • https://sk-developers.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609b06af9219e---xalujedixezumowizibonube.pdf
    • http://dlevitin.ru/fck_editor_files/files/38489963461.pdf
    • https://growlocals.com/wp-content/plugins/super-forms/uploads/php/files/d92f881a246d682aa5de424a9c5f75d2/zewimidutotedar.pdf
    • https://n-zvuk.ru/upload/file/99620237091.pdf
    • https://amartzon.store/wp-content/plugins/super-forms/uploads/php/files/3100d19539c2e8535f0c33bdcf6f71ff/5785646530.pdf
    • https://dolmalatrek.com/userfiles/file/76359656186.pdf
    • http://mfcwestenkwartier.nl/beta/userfiles/file/kuwagukugoxinetix.pdf
    • https://suemsas.com/wp-content/plugins/super-forms/uploads/php/files/sppi8sdeq1l1f2cqbam9cge0k6/dewibulaxoxasomufetagezo.pdf
    • https://bizdrive.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1/1607ec22925c60---46529538669.pdf
    • https://opuntia.eu/wp-content/plugins/super-forms/uploads/php/files/204c817c8d56c4505eb56866e3323658/fewed.pdf
    • http://fantasypartyentertainment.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607dbe1d4dc51---48171235085.pdf
    • https://yarsan.ru/wp-content/plugins/super-forms/uploads/php/files/c440cf037b68390d164db95369513d04/wetoxivebegavizuvif.pdf
    • http://itssilvertime.com/clients/2/24/24efe347a73a8ce028152bf895bc11a7/File/bogogupudajonaduzutilowu.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/3vuEKuznOb8/uplcv?utm_term=convert+sq+feet+to+square+meter
    • 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_off0000c369.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xC369 16792 bytes
font_01_sfnt_off0000db80.bin
0bdae0492379efd6facf1589020a1b880d3e0c63532bd7abcd701a8ce13437ca
pdf-font-stream PDF embedded font (sfnt) at offset 0xDB80 10580 bytes
font_02_sfnt_off0000f3be.bin
89e21762c5151aacff3b5bc978b0437a78f794e950fbf5f2df3fad676ca1cba8
pdf-font-stream PDF embedded font (sfnt) at offset 0xF3BE 16264 bytes