Malicious PDF — malware analysis report

Static analysis result for SHA-256 440a82a77c75d0a6…

MALICIOUS

PDF

72.7 KB Created: 2021-09-19 02:41:43 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: bcaedd78d5f45702bc899e1e1709b435 SHA-1: 39eda758fb67d7234ce5926361b061b169e52d96 SHA-256: 440a82a77c75d0a6ef641bbb068ed34808c429c64207cd4102e8d268f8bac22f
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It contains a link farm pointing to multiple compromised websites, suggesting an attempt to redirect users to download further malicious content. The presence of numerous PDF_SEO_DISPOSABLE_LINK_FARM and PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM heuristics further supports this attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9992

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://sumangold.net.vn/wp-content/plugins/super-forms/uploads/php/files/gnkmdpfg0vfkr0mpvr4p7vp0rc/minodugedefuletunopotamal.pdf In PDF document text
    • http://3sdent.com/upload/files/judasotazabaxadefu.pdfIn PDF document text
    • https://mytopics.it/uploads/file/49134664162.pdfIn PDF document text
    • http://oneself.pro/wp-content/plugins/formcraft/file-upload/server/content/files/16131350cccffc---53589110097.pdfIn PDF document text
    • http://honeystraw.com/uploadfiles/file/58840366230.pdfIn PDF document text
    • https://bawaniint.com/ckfinder/userfiles/files/85476284789.pdfIn PDF document text
    • http://aqs-group.it/userfiles/files/95116685946.pdfIn PDF document text
    • https://sharks-cz.cz/images/file/77216849840.pdfIn PDF document text
    • https://kingyao.com/uploadfiles/files/20210910_105702_5787.pdfIn PDF document text
    • http://sklepjola.pl/userfiles/file/82666101913.pdfIn PDF document text
    • http://sherwoodchambergolf.com/ckfinder/userfiles/files/ximujenirawawuwutubek.pdfIn PDF document text
    • http://wittymall.com/multimedia/userfiles/file/26549709997.pdfIn PDF document text
    • https://callmarkinvestments.fortunekenya.com/callmark/files/60979953818.pdfIn PDF document text
    • http://champagne-marc-chauvet.com/images/files/13671106458.pdfIn PDF document text
    • https://cosplay-expo.it/ckfinder/userfiles/files/49016416519.pdfIn PDF document text
    • https://rinducm1.com/contents/files/sabetu.pdfIn PDF document text
    • http://izeninfo.net/admin/upload/files/39954616190.pdfIn PDF document text
    • https://shrmivirtual.org/wp-content/plugins/super-forms/uploads/php/files/e9872323bf821038affb2d60d311d0ac/79215472751.pdfIn PDF document text
    • http://omgmediatank.com/userfiles/files/nigebozexigepitawesaje.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/PmAiG5ZyT-k/uplcv?utm_term=ball+sort+puzzle+mod+apkPDF 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_off0000b83e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB83E 17228 bytes
SHA-256: 2064ab24767b3cd66be1e66035bc857882bb48dd467f673adc8d0d7710aa9ccb
font_01_sfnt_off0000e4d3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE4D3 10664 bytes
SHA-256: 8cf76334583e7cafe2734ed42b8d44461d7999b4cae83428d563f1fb5780194a
font_02_sfnt_off0000fd71.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFD71 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1