Malicious PDF — malware analysis report

Static analysis result for SHA-256 d8d2a38881e1cd18…

MALICIOUS

PDF

71.5 KB Created: 2021-09-25 06:48:50 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: 64c4ff691207a1d1e2f6a9c122798e63 SHA-1: 3afcb8d6a4ae30b1c83e74bf0fabd61ad3b936eb SHA-256: d8d2a38881e1cd185241f5c4a6e672789d4f8ba7f2218794b9eb986cf0457ec0
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF document was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. It contains numerous embedded URLs that form a link farm, pointing to compromised CMS uploads and disposable hosting, suggesting an attempt to redirect users to malicious sites. While no scripts were explicitly extracted, the nature of the link farm and the detection indicate a phishing or malware distribution attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9956

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://pistant.ru/uplcv?utm_term=characteristics+of+prokaryotic+and+eukaryotic+cells PDF link annotation
    • http://forumts.com/ckfinder/userfiles/files/54544329182.pdfIn PDF document text
    • http://totalfinance.ca/wp-content/plugins/formcraft/file-upload/server/content/files/161421890388e0---mumagakemib.pdfIn PDF document text
    • http://barahi.com/assets/userfiles/files/vuzodadevoxag.pdfIn PDF document text
    • http://brkvinc.com/userfiles/file/22353436619.pdfIn PDF document text
    • http://windcampus.com/wp-content/plugins/formcraft/file-upload/server/content/files/161386e22b1e8b---26192423583.pdfIn PDF document text
    • http://markjfox.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/35062026223.pdfIn PDF document text
    • http://bighost.vn/uploads/userfiles/file/78485814140.pdfIn PDF document text
    • http://ozdoby-betonowe21.pl/Upload/file/punodunip.pdfIn PDF document text
    • http://www.psyforyou.nl/upload/fckeditor/file/6394900201.pdfIn PDF document text
    • https://barrier.exma.cl/ckfinder/userfiles/files/tewuroxuguletagotop.pdfIn PDF document text
    • https://www.mppoa.cloudlinesystems.com/assets/ckfinder/userfiles/files/71791979234.pdfIn PDF document text
    • http://belean.pl/userfiles/file/24592114409.pdfIn PDF document text
    • http://stlukesfp.org/ckfinder/userfiles/files/42327824037.pdfIn PDF document text
    • https://www.accidentinjuryalbuquerque.com/wp-content/plugins/super-forms/uploads/php/files/qevv6mi0murjalkg0guc581eaq/jusewufaxuxux.pdfIn PDF document text
    • http://dentish.ru/ckfinder/userfiles/files/58496249478.pdfIn PDF document text
    • https://yesilkoyluleriz.biz/resimler/files/76787033699.pdfIn PDF document text
    • http://cobe-ing.it/userfiles/files/57078518256.pdfIn PDF document text
    • http://csc-0411.com/userfiles/file/20210911110245_bfl6vc.pdfIn PDF document text
    • http://ge-mak.com/files/82964698993.pdfIn PDF document text
    • http://80tner.friend-match.com/upload/files/subobi.pdfIn PDF document text
    • https://ecohort.biz/userfiles/files/gewimubenap.pdfIn PDF document text
    • https://marsanz.pl/uploads/fck/file/47306449018.pdfIn PDF document text
    • http://kystop.com/wp-content/plugins/super-forms/uploads/php/files/f14372ae3f7d13fd3ed464fe45cd638c/51978892956.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_off0000b122.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB122 11056 bytes
SHA-256: 12013f54f94555045b90eea6f9f5b98d450e005d487a354a1ec9d2a990f8af63
font_01_sfnt_off0000cadd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCADD 17776 bytes
SHA-256: 59084e1e41f0ba9b24be4045f0b7930e1b4f0551db0c4a9432dd7da59588f4af
font_02_sfnt_off0000f7ef.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF7EF 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1