Malicious PDF — malware analysis report

Static analysis result for SHA-256 0b791cc86cd21ec2…

MALICIOUS

PDF

72.0 KB Created: 2021-09-20 07:59:34 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: f53a43c49f7602faffa338f8d2c8cc1a SHA-1: 3bdbc3b13ecb2395a99ff4ced512551656181c65 SHA-256: 0b791cc86cd21ec22dd47035d2d9e34aaa047f53d188d42d2f6792146581182c
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample was detected as malicious by ClamAV and an ML classifier, and exhibits characteristics of a link farm pointing to potentially compromised WordPress upload directories. The embedded JavaScript stream (PDF_JS) likely facilitates the redirection to these external URLs, which are designed to lure users into downloading further malicious content or providing sensitive information.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9971

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 http://www.davidwoodpersonnel.com/wp-content/plugins/formcraft/file-upload/server/content/files/161365ddc1e575---89733015424.pdf
    • https://cissud.com/uploads/ck_editor/files/gakipejixadazavaliduxi.pdf
    • http://nanoscopy.ru/uploads/files/zusadale.pdf
    • https://goodmix-psc.com/userfiles/files/35330681442.pdf
    • http://akifkasaboglu.com/esatfisek/images_upload/files/zizakedupisoz.pdf
    • http://opusincertum.it/userfiles/files/15268291515.pdf
    • https://cesiedizioni.com/userfiles/file/16587476574.pdf
    • http://paintmaster.hu/js/ckfinder/userfiles/files/58677903487.pdf
    • http://generaltubi.com/container/ckfiles/files/ganixelexogemu.pdf
    • http://twilaw.com/files/files/15396887217.pdf
    • https://majubesar.org/contents/files/bopoledepuka.pdf
    • http://prepearl.com/uploadsfile/64899313977.pdf
    • http://tsutae-f.com/js/upload/files/5457238683.pdf
    • http://www.studiolegalefusimorelli.com/wp-content/plugins/formcraft/file-upload/server/content/files/161353bdbaa213---foziwenetuzukagemaf.pdf
    • http://dinskayarealty.ru/media/file/vubokafawaxeradapevaw.pdf
    • http://skpizzasubs.com/uploads/files/8767897028.pdf
    • https://harpethvalleypto.org/wp-content/plugins/super-forms/uploads/php/files/c83b7e58ad0048768bdebabeae4f1353/tiruxizikedi.pdf
    • http://clinical-pain.com/pds/userfiles/files/24848421371.pdf
    • https://vaynhanh365.net/contents/files/kidoxitudixasapomu.pdf
    • https://parlagame.com/calisma2/files/uploads/10003810302.pdf
    • https://maydongy.com/wp-content/plugins/super-forms/uploads/php/files/0bo3r91u6sngu72fpntareri9v/7311247647.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/PmAiG5ZyT-k/uplcv?utm_term=sarasate+zigeunerweisen+violin+sheet+music
    • 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_off0000b26e.bin
c35a98016e9308dc9ec807666eef1b42bc9c13606d903a07925e46a1f715179d
pdf-font-stream PDF embedded font (sfnt) at offset 0xB26E 18316 bytes
font_01_sfnt_off0000e11c.bin
8e2898ab30a912bb9048f75dc29371d58566d66c484e66855762f34b1de2dbdd
pdf-font-stream PDF embedded font (sfnt) at offset 0xE11C 11064 bytes
font_02_sfnt_off0000facb.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xFACB 16792 bytes