Malicious PDF — malware analysis report

Static analysis result for SHA-256 8daac531b9debb2c…

MALICIOUS

PDF

82.7 KB Created: 2021-09-18 09:20:51 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: a8049f4f1ba3a67fa62fbed85c15de88 SHA-1: 525745fcc650beca288132dc358dadbbff802088 SHA-256: 8daac531b9debb2cf2af974fa443a678e345396c3bb5def8c73e4d02a575138e
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file was detected as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. It contains numerous embedded URLs, many pointing to PDF files on various domains, suggesting a link farm or redirection mechanism. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' specifically flags the PDF for containing many links on disposable hosting, reinforcing the phishing or malware distribution vector. While no scripts were explicitly extracted, the nature of the embedded URLs and the ML detection suggest it may exploit PDF vulnerabilities or employ JavaScript for malicious actions.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9964

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://mobiligennari.com/userfiles/file/77550690773.pdf In PDF document text
    • https://fzclicks.com/demo/files/editor/file/purofalarelazamiw.pdfIn PDF document text
    • http://nscenter.cn/upload/files/28085256798.pdfIn PDF document text
    • http://tabbanbros.com/admin/fckeditor/editor/filemanager/connectors/upload/file/xidetudisarofalamaw.pdfIn PDF document text
    • https://maria-galland.ru/files/file/42066390112.pdfIn PDF document text
    • http://dulichtantai.com/files/uploaded/files/6809753158.pdfIn PDF document text
    • http://inwallendorf.de/userfiles/file/72748916253.pdfIn PDF document text
    • http://www.iece.in/userfiles/file/zamafetowumix.pdfIn PDF document text
    • https://gtijsr.com/userfiles/file/gigerozo.pdfIn PDF document text
    • http://sushikyototogo.com/uploads/files/9336051827.pdfIn PDF document text
    • http://gonvvama.net/filespath/files/20210918052903.pdfIn PDF document text
    • http://cityfate.com/files/files/82351062155.pdfIn PDF document text
    • http://aliancegroup.su/wp-content/plugins/formcraft/file-upload/server/content/files/161452ab642d72---21199961694.pdfIn PDF document text
    • http://haki.vn/uploads/files/94170433386.pdfIn PDF document text
    • https://tssch.in/tssch/application/admin/uploads/file/5276955043.pdfIn PDF document text
    • http://xn--80aafjbawrcdgsodbdciig4a5v.xn--p1ai/pict/file/vumoko.pdfIn PDF document text
    • https://californiaoptionsrealestate.com/wp-content/plugins/super-forms/uploads/php/files/6c2f30cd837ce4a06e633027f4a91345/81013868004.pdfIn PDF document text
    • http://gianenricofabro.com/userfiles/files/27664219756.pdfIn PDF document text
    • http://ahcxdq.com/uploads/file/090547542241.pdfIn PDF document text
    • http://tyextractor.com/d/files/sasogusifavetafu.pdfIn PDF document text
    • http://jongauger.com/userfiles/file/92170020788.pdfIn PDF document text
    • http://cjcounsel.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/4885031055.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/LPIa9PGmDLg/uplcv?utm_term=how+to+write+a+concluding+statementPDF link annotation
    • 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_off0000df3b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDF3B 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f74d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF74D 17400 bytes
SHA-256: 2e29e20432fe0d069a6aab3872078ec1e909a5865f5e346cccaf2973d40f9049
font_02_sfnt_off00012476.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12476 10892 bytes
SHA-256: f69573ea86d6ba492f50073675d443cd26a18d5da1e75dde7406ec3a9b2b287d