Malicious PDF — malware analysis report

Static analysis result for SHA-256 83efee5c44d9294c…

MALICIOUS

PDF

82.0 KB Created: 2021-09-06 09:37:14 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 82480859eb4de5a63b627b7f8fc12797 SHA-1: 3f3b9a9bac50fd2c102c34da6be1262aca4ea0ac SHA-256: 83efee5c44d9294c685a2ce3624f5265a8fffa3927bbbf7624700e6ca83eb14e
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample was detected as malicious by ClamAV and ML classifiers, indicating a high likelihood of malicious intent. The PDF contains embedded JavaScript, which is often used to exploit vulnerabilities or redirect users. Furthermore, the presence of a link farm pointing to multiple distinct hosts, some of which are compromised WordPress uploads, suggests an attempt to obscure the final destination and distribute malicious content or phishing lures.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

Heuristics 7

  • 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.
  • 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://trungtammatnamviet.vn/upload/files/tuvawiti.pdf
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/160819ac153e0b---98113576537.pdf
    • https://cjsc.se/ckfinder/userfiles/files/jabotujotu.pdf
    • https://ystechpro.com/nbloom/fckuploads/file/nigawovo.pdf
    • http://dobrejaja.com/Upload/file/47656657697.pdf
    • http://www.kzhep.in.ua/wp-content/plugins/super-forms/uploads/php/files/qp4f2178uhggrj1vo6kujfh301/20400269380.pdf
    • http://profisystem.ro/wp-content/plugins/formcraft/file-upload/server/content/files/160c658bc0721f---lezanubepumixo.pdf
    • https://edoxmarketing.com/wp-content/plugins/super-forms/uploads/php/files/k3njq79amebunnn9ld620dpa1j/25389212180.pdf
    • http://webinaris.eu/ckfinder/userfiles/publics/files/70396227551.pdf
    • http://carshopm.com/js/upload/files/simukekufutere.pdf
    • https://wills.sg/wp-content/plugins/super-forms/uploads/php/files/6466209502b073548f18fdb72b263c07/romiwil.pdf
    • http://remontnoedelo.ru/wp-content/plugins/formcraft/file-upload/server/content/files/1609b73c475fe7---67099857308.pdf
    • https://www.grandiosa.is/wp-content/plugins/super-forms/uploads/php/files/5sf370ps9v3fgmp253t33fosp3/sidaxavadapokefe.pdf
    • http://wernersuarez.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/ludigeje.pdf
    • https://yennenga.org/business_school/uploads/file/bimitamujuwamamoveziv.pdf
    • https://alignerco.com/wp-content/plugins/super-forms/uploads/php/files/c735fca7eb26df839f807c19e5f15b7b/fawumitaxabifalipisutibid.pdf
    • http://www.morenoroofing.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608704b3754f2---43524694554.pdf
    • http://www.absolutecateringla.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606c68feb556b---muxasekewokidisegitijo.pdf
    • http://multiseal.com.ph/wp-content/plugins/formcraft/file-upload/server/content/files/1607a04a7bec68---vakufivi.pdf
    • https://108pizza.pl/uploads/userfiles/files/45416853497.pdf
    • http://agiusfuneraldirectors.com/files/file/12081674333.pdf
    • http://camberwelltaxi.com/survey/userfiles/files/finagi.pdf
    • https://elmaga.lt/components/com_mijoshop/opencart/image/data/files/lamiwusezixavedugaxuvapo.pdf
    • http://kuhomania.ru/ckfinder/userfiles/files/46033770107.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/S30rS-6n6vg/uplcv?utm_term=indicaciones+de+urografia+excretora+pdf
    • 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_off0000d89e.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xD89E 16792 bytes
font_01_sfnt_off0000f0b5.bin
775dd0673a633c3370fbccb825e6b504a3b67e31d2f658aa0d65a6f140aca664
pdf-font-stream PDF embedded font (sfnt) at offset 0xF0B5 10904 bytes
font_02_sfnt_off000109e1.bin
fc71930a07907b2f0f0dcd665416bdf13680b8f949df3a330877d5847f060aab
pdf-font-stream PDF embedded font (sfnt) at offset 0x109E1 18980 bytes