Malicious PDF — malware analysis report

Static analysis result for SHA-256 8911475e23a2ae9c…

MALICIOUS

PDF

81.7 KB Created: 2021-09-09 14:21:29 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 0126db8cfc35e9c7c68745cce30d7334 SHA-1: 68b056c415683bddec1a20f5cf34652e8ac7c29f SHA-256: 8911475e23a2ae9c249bfdc6ebd1dd18de98b515f449892fe3d2f9f4f8d6de3b
164 Risk Score

Malware Insights

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

The PDF file was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, directing users to various external sites, some of which are hosted on compromised WordPress infrastructure. The presence of a 'download button' lure further supports a phishing or malware distribution attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9955

Heuristics 7

  • 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.
  • Visual download / call-to-action button lure low SE_DOWNLOAD_BUTTON
    Document contains a call-to-action phrase ('Click here to download', 'Download Now', etc.) — low-signal unless other findings point to a malicious workflow
  • 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 http://szjwwj.com/userfiles/file///35867924935.pdf
    • http://rakkhunnursinghome.com/user_img/files/23583701138.pdf
    • http://pk.mo/userfiles/file/vurobidowodamukoxofu.pdf
    • http://paradoxine.com/upload/files/53193299718.pdf
    • http://franceplus.fr/userfiles/file/15529873758.pdf
    • http://nanoservice.cz/upload/file/3440988113.pdf
    • http://www.lebedosapartotel.com/data/yukle/files/98079327835.pdf
    • https://borderpak.com/wp-content/plugins/super-forms/uploads/php/files/f4544cf44633f6e89412c6f345cdf995/sironuwobalokog.pdf
    • http://ayurvedicclinic.org/userfiles/file/50431821342.pdf
    • http://chanhungcorp.com/images/uploads/files/60066422525.pdf
    • https://yantrasearch.com/ckfinder/userfiles/files/13812100753.pdf
    • http://constantemail.com/userfiles/file/163079002832564732609.pdf
    • https://uclerbaklava.com/resources/file/30307914296.pdf
    • https://cyc-catering.pe/disac/userfiles/file/30613306516.pdf
    • http://evabody.ro/wp-content/plugins/formcraft/file-upload/server/content/files/16134afa5c1bd8---17229562395.pdf
    • https://chokysitohang.com/Uploads/userfiles/files/rokizigijinutojaxifajef.pdf
    • http://mfo-fond.ru/ckeditor/ckfinder/userfiles/Images/files/37093736672.pdf
    • http://mbeautyconcept.com/upload/content_images/file/lolunasitibenoxumipises.pdf
    • http://kleinschadenexpert.com/userfiles/file/87728812213.pdf
    • http://daltan.hu/userfiles/file/58035570799.pdf
    • https://petroblend.com/wp-content/plugins/formcraft/file-upload/server/content/files/16139e61b26906---31928225757.pdf
    • https://www.karenlovelee.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612f506b461d1---lovuvejarujez.pdf
    • https://cissud.com/uploads/ck_editor/files/33287030607.pdf
    • https://speakingparrot.com/upload/ckfinder/files/sopumamona.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/S30rS-6n6vg/uplcv?utm_term=windows+8+oem+product+key
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000d9f7.bin
5708229d49923565ca16289650d0599403326e5f53071a95f71c64e0cfd2dc73
pdf-font-stream PDF embedded font (sfnt) at offset 0xD9F7 17776 bytes
font_01_sfnt_off00010785.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x10785 16792 bytes
font_02_sfnt_off00011f9c.bin
10474478a5de17797851a90b2d3a1d79caa859166294d929a999aed3d3d36be5
pdf-font-stream PDF embedded font (sfnt) at offset 0x11F9C 11060 bytes