Malicious PDF — malware analysis report

Static analysis result for SHA-256 7ef452aaeff54cd2…

MALICIOUS

PDF

71.0 KB Created: 2021-10-03 03:35:54 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-24
MD5: 6e604fc648629303498bae7fb4ac7115 SHA-1: b26670da5c93ee13264f646d51732a2ccceaad60 SHA-256: 7ef452aaeff54cd24baaa7b31520042ea513fe387042cba686009faf067bf8c9
156 Risk Score

Malware Insights

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

The file was detected as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. It contains numerous external URLs, many hosted on what appear to be compromised websites or disposable domains, suggesting a link farm designed to redirect users. The presence of PDF-specific heuristics like 'PDF_SEO_DISPOSABLE_LINK_FARM' and 'PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM' further supports the conclusion that this PDF is part of a phishing or malware distribution scheme.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

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 https://chcial.ru/uplcv?utm_term=acculturation+definition+sociology PDF link annotation
    • https://frutalmente.pt/site/upload/file/96295456305.pdfIn PDF document text
    • http://dream-mebel.com/pic/file/gutew.pdfIn PDF document text
    • http://www.cuerpomenteyespiritu.es/wp-content/plugins/formcraft/file-upload/server/content/files/16135d6299ffe6---82322398908.pdfIn PDF document text
    • http://danguykhoidoanhnghiephp.vn/Upload/files/65278471791.pdfIn PDF document text
    • http://ceramvetro.net/userfiles/file/82806956204.pdfIn PDF document text
    • http://cuanhuadanang.vn/uploads/image/files/botater.pdfIn PDF document text
    • http://mcserpenti.com/userfiles/file/89128857476.pdfIn PDF document text
    • https://candbco.com/ckfinder/userfiles/files/43441748335.pdfIn PDF document text
    • http://camelliafb.com/uploads/files/202109141801053768.pdfIn PDF document text
    • http://studiostocchi.eu/userfiles/files/ragifaxotuwunikukaned.pdfIn PDF document text
    • http://shepardinteriordesign.com/rw/upload/file/73482478660.pdfIn PDF document text
    • http://wccflooring.com/userfiles/files/nigazi.pdfIn PDF document text
    • http://mptech.vn/ckfinder/userfiles/files/94319987063.pdfIn PDF document text
    • https://macleanpinesdrivingschool.com.au/wp-content/plugins/super-forms/uploads/php/files/248e0b7afb3b9d0fde746dcc4dccfdaf/junanarejitodokug.pdfIn PDF document text
    • https://aksusu.com/upload/files/14056116317.pdfIn PDF document text
    • http://tw-jia.com/uploads/files/202109232249513744.pdfIn PDF document text
    • http://tolaniprojects.com/userfiles/file/97140861880.pdfIn PDF document text
    • https://callmarkinvestments.com/callmark/files/41499251269.pdfIn PDF document text
    • https://sarenpinler.com/calisma2/files/uploads/sikerumuxame.pdfIn PDF document text
    • https://sketchup360.vn/wp-content/plugins/super-forms/uploads/php/files/jlgrvvr3u98dus83pdpfe64sre/rinete.pdfIn PDF document text
    • http://basumati.com/app/webroot/ckfinder/userfiles/files/92261004659.pdfIn PDF document text
    • http://businessplan-capalpha.eu/mbp/upload/images/images/upload/ckfinder/migatuveto.pdfIn PDF document text
    • http://paykaaluminiya.ru/ckfinder/userfiles/files/dutipulezorafo.pdfIn PDF document text
    • http://rent-lease-no1.com/userfiles/file/20210912023017.pdfIn PDF document text
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#In PDF document text
    • http://purl.org/dc/elements/1.1/In PDF document text
    • http://ns.adobe.com/pdf/1.3/In PDF document text
    • http://ns.adobe.com/xap/1.0/In PDF document text
    • http://ns.adobe.com/xap/1.0/mm/In PDF document text
    • http://ns.adobe.com/xap/1.0/rights/In PDF document text
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000b508.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB508 15924 bytes
SHA-256: df01555f4eca889d9fb88719f7e8cd2e1498b8f7a491d238385eb1e4c5c960e1
font_01_sfnt_off0000dd1f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDD1F 10848 bytes
SHA-256: 581645e780b84c1300a9155cb3be8539e716c13752cec8b9427f602b41e8b4f8
font_02_sfnt_off0000f623.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF623 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1