Malicious PDF — malware analysis report

Static analysis result for SHA-256 686c6d7cb7930118…

MALICIOUS

PDF

87.9 KB Created: 2021-09-11 15:01:11 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: b146fab26d49a47c659a4914576415f8 SHA-1: ef5f39ca7705ba5b518a90ef0c7dd33f1ea7ff8d SHA-256: 686c6d7cb793011868e26c87eb2dd5c7657f2403e43e27ca3b89e371e69a8fa7
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF file was flagged by ClamAV as 'Pdf.Phishing.Trojan' and a machine learning classifier indicated a high probability of maliciousness. Heuristics identified the document as a link farm, with many external URLs pointing to potentially compromised WordPress upload directories or disposable hosting. The document body was unreadable, but the presence of numerous links suggests an attempt to redirect users to malicious sites, likely for phishing or to download further malware.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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://1hozain.ru/files/userfiles/files/99282169176.pdf
    • http://www.lovebliss.tw/UserFiles/files/78868154667.pdf
    • http://synphabase.ch/upload/file/tevusezafi.pdf
    • https://ngusacdon.com/upload/files/guribasufemixuvixibumu.pdf
    • http://startent.ru/SITE/files/editor/file/58665487813.pdf
    • http://www.kinoimaging.nl/wp-content/plugins/formcraft/file-upload/server/content/files/161337b1ec0e67---36137704026.pdf
    • https://promaxsuspension.com/csmimage/file/tujidikuto.pdf
    • http://watchimport.eu/userfiles/file/fusivojovola.pdf
    • http://morebricks.com/ckfinder/userfiles/files/xogowuvaliluzemukoma.pdf
    • http://caribsplash.org/wp-content/plugins/formcraft/file-upload/server/content/files/1613ad66d634be---mugotomodowuwig.pdf
    • http://limpiasol.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613190ed5d4c7---walujopage.pdf
    • http://twfbs.com/ckfinder/userfiles/files/kemapasasenavanunovep.pdf
    • https://aspirans.com/files/file/26708404085.pdf
    • http://cn-daomeng.com/upload/userfiles/files/3eebc014fa70b29089c7303ab9cbe8b7.pdf
    • https://www.modianodesign.com/wp-content/plugins/formcraft/file-upload/server/content/files/161334eeb97df8---75161081057.pdf
    • https://moveo-sport.pl/userfiles/file/rubarudagikore.pdf
    • https://tucarrorentacar.co/ckfinder/userfiles/files/78875287086.pdf
    • https://xyoaa.org/sites/default/files/files/gemeraviradafajorunutim.pdf
    • https://centar-znr-zop.hr/wp-content/plugins/formcraft/file-upload/server/content/files/16135bb5bdc26c---siwilevediwexuzusug.pdf
    • https://laxmigrouppune.com/wp-content/plugins/super-forms/uploads/php/files/d22d9602eb7a8c86521a142c0b6fe63e/30626017462.pdf
    • https://minjar.mebel18.com/uploads/files/vejutonawunulawobudemem.pdf
    • https://girilawfirm.com/content_files/files/90193791023.pdf
    • http://hitechdentalhouston.com/uploads/files/fopesokomumusi.pdf
    • https://mtydizayn.com/userfiles/file/fisobusaxinej.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/GLLx1DTH0VQ/uplcv?utm_term=speedy+dns+changer
    • 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_off0000f195.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xF195 16792 bytes
font_01_sfnt_off000109ac.bin
997fa2bdb3f2642de54ab74a53af2a15d8b149eb9397f70b55e02eb022effd53
pdf-font-stream PDF embedded font (sfnt) at offset 0x109AC 10628 bytes
font_02_sfnt_off000121b1.bin
245c745610819c17667071bca093c1c7fc60da2d7eeb2b0983bdfc6dbffc9e2b
pdf-font-stream PDF embedded font (sfnt) at offset 0x121B1 18496 bytes