Malicious PDF — malware analysis report

Static analysis result for SHA-256 6bafe4d984a41b99…

MALICIOUS

PDF

81.1 KB Created: 2021-09-21 01:44:10 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: cd322555bf4775555811e47ffaaec2ed SHA-1: 8ef37c4981763c053f968566fad471a24648b320 SHA-256: 6bafe4d984a41b99f6d0903cedc6933b4af5593af8a6ebb133f5a6960a0007ed
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs, many of which point to compromised WordPress sites or disposable hosting, indicating a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely phishing or malware distribution. No scripts were extracted, but the PDF structure itself facilitates the attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9955

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 http://www.psstrecno.sk/wp-content/plugins/formcraft/file-upload/server/content/files/16147c9bc52aa2---muwesakopogozodam.pdf
    • https://hamzakocakoglu.com/userfiles/file/linemuvukomupumoxewag.pdf
    • http://vln.nl/files/file/fetexemagefitojadinigelem.pdf
    • https://ultralloy.net/upload/files/nezaragugilusabusi.pdf
    • http://kim-clark.ru/files/file/25426910956.pdf
    • https://shaplaconsulting.com/app/webroot/ckfinder/userfiles/files/1638615054.pdf
    • http://mudrkanuch.sk/editor_uploads/system/files/26154219524.pdf
    • http://tsyrulnikov.ru/upload/file/2094931833.pdf
    • https://self-storage.sg/images/uploadedimages/file/delinawifovavisuwijukuve.pdf
    • https://wholisticvibrations.com/wp-content/plugins/super-forms/uploads/php/files/490a1b34468999d96bd50a929719e5b2/gulolubege.pdf
    • http://kidneytracker.com/ckfinder/userfiles/files/90991019831.pdf
    • http://es-manzokudou.com/yamituki-n/uploads/files/88035451929.pdf
    • http://bikaji.zohukum.com/ckfinder/userfiles/files/niloronogokod.pdf
    • http://ascensionchina.com/userfiles/file/faxabipuper.pdf
    • http://montesantangelo.it/files/files/petizejupatolilodesiv.pdf
    • http://unitekinfostructures.com/userfiles/file/68380509046.pdf
    • http://gruaszarate.com/ckfinder/userfiles/files/kalutidakirixiwida.pdf
    • https://www.lsv-wittlage.de/ckfinder/userfiles/files/22609171817.pdf
    • https://chaletsuenodesol.de/files/1573393507.pdf
    • http://closehorses.com/userfiles/file/95546720084.pdf
    • http://fli.edu.mn/ckfinder/userfiles/files/fuliji.pdf
    • http://ifa-astrologie.de/userfiles/file/tegefiz.pdf
    • https://beamstraffic.com/amb/userfiles/file/25372288023.pdf
    • http://www.mtpartnersfl.com/wp-content/plugins/formcraft/file-upload/server/content/files/161485871b2343---84478691783.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/LPIa9PGmDLg/uplcv?utm_term=how+to+get+contacts+back+on+android
    • 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_off0000d719.bin
d9b45343aecfa70acbe72e25ddf8f8d9e19460cd2f2559c9475fbe1f41656229
pdf-font-stream PDF embedded font (sfnt) at offset 0xD719 10808 bytes
font_01_sfnt_off0000f002.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xF002 16792 bytes
font_02_sfnt_off00010814.bin
0ad20945a944d9fa1d490a99f8004184510711d8b9171824c1f6882227f03c72
pdf-font-stream PDF embedded font (sfnt) at offset 0x10814 18184 bytes