Malicious PDF — malware analysis report

Static analysis result for SHA-256 81b263290ff4a516…

MALICIOUS

PDF

92.4 KB Created: 2021-09-09 00:23:11 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: ff042f8f680878619b3fb4fbb346e814 SHA-1: f9a30ff3cbceafc4e9c1a3f1357585fd6e374878 SHA-256: 81b263290ff4a5164f799b86878c44260b8ea8273dc4eaa18e7d7720bc591f38
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF was flagged by ML classifiers and ClamAV as malicious, exhibiting characteristics of a link farm. It contains numerous external URIs, many pointing to disposable domains, suggesting an attempt to obscure the true destination or distribute various payloads. The presence of embedded JavaScript, though not fully analyzed here, likely contributes to the malicious functionality by facilitating redirection or exploitation.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9905

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://tucsonhomewindowtint.com/wp-content/plugins/super-forms/uploads/php/files/2aa87e50a8becb249f2ba497e50c49d6/71725536772.pdf In PDF document text
    • https://fultoys.com/userfiles/buwiferevunex.pdfIn PDF document text
    • http://stuarteisbrucklaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/82142037472.pdfIn PDF document text
    • https://12tiga.com/contents/files/62226095774.pdfIn PDF document text
    • http://energcomb.net/cms_enercomb/sgi_userfiles/userfiles/files/60183156056.pdfIn PDF document text
    • https://morganmethod.com/ci/userfiles/files/34241291332.pdfIn PDF document text
    • http://lobi.md/userfiles/file/95892131704.pdfIn PDF document text
    • https://thinkglobalcompliance.com/ckfinder/userfiles/files/jizub.pdfIn PDF document text
    • http://royalgoodviewresort.com/Uploads/file/31096515702.pdfIn PDF document text
    • http://liubeauty.com/luutru/files/97348635479.pdfIn PDF document text
    • http://www.tobywells.org/media/fckdir/file/tunebiv.pdfIn PDF document text
    • http://biolabsrl.org/userfiles/files/43571527927.pdfIn PDF document text
    • http://qdxqw.com/uploadfile/file/63807494127.pdfIn PDF document text
    • https://eastoncn.housemember.com/uploads/files/54502172123.pdfIn PDF document text
    • http://greenlivinggarden.com/htdocs/UserFiles/file/87484616663.pdfIn PDF document text
    • http://cellesekorea.com/ckupload/files/15036668088.pdfIn PDF document text
    • http://studiotecniconuti.it/userfiles/files/6297336340.pdfIn PDF document text
    • https://majubesar.info/contents/files/36085051520.pdfIn PDF document text
    • http://lexxyin.net/files/fckeditor/file/torafejutop.pdfIn PDF document text
    • https://castilloexterior.es/ckfinder/userfiles/files/xoruvufenulex.pdfIn PDF document text
    • http://phuocthuan.vn/images/pic/file/28865188462.pdfIn PDF document text
    • https://stotex.rs/files/72395661200.pdfIn PDF document text
    • https://wilocom.ro/ckfinder/userfiles/files/3815714066.pdfIn PDF document text
    • http://sumisaedu.com/FileData/ckfinder/files/20210908_75686A69C2C807A9.pdfIn PDF document text
    • https://webhostmurah.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613355b67a5ca---26722342805.pdfIn PDF document text
    • https://wangwangcamp.com/uploads/files/202109011438078900.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/A3Ryygt5BCM/uplcv?utm_term=movies+to+download+freePDF 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_off000106f8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x106F8 17360 bytes
SHA-256: e4670a2b7c4de0f2e272eac0ff5bad3caad929b940fed8d34f2b8bcb95dc2565
font_01_sfnt_off000133e9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x133E9 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00014c00.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x14C00 10492 bytes
SHA-256: 2d4f5c3d1b0f9160c572ea7b0a8ef30512666e16e9ee67738e55d5143cf927c7