Malicious PDF — malware analysis report

Static analysis result for SHA-256 b157e5e1303f6806…

MALICIOUS

PDF

87.2 KB Created: 2021-09-17 19:51:10 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: a4f58019f12d3d46a0af97eb0e0060ad SHA-1: 7577d2b79d2e7cf1b524616bf156732de43461a1 SHA-256: b157e5e1303f68066091bdedd23a7dc6a4e4d0f1baea731c8fdaed7873fe8aff
126 Risk Score

Malware Insights

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

The PDF was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. It contains numerous embedded URLs, many of which point to disposable domains and form a link farm, a common tactic for phishing or distributing further malware. The presence of external URIs and the link farm structure strongly suggest an attempt to redirect the user to a malicious site.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9976

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 http://sunwisechem.com/Uploadfiles/files/tomosevufupusiv.pdf In PDF document text
    • https://ijp2.com/contents/files/78582695079.pdfIn PDF document text
    • http://johnlillylaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/58535850246.pdfIn PDF document text
    • http://5thaveseniors.org/userfiles/file/vasejivimetoxumurisadu.pdfIn PDF document text
    • http://vitcongiong.com/uploads/files/12353062350.pdfIn PDF document text
    • https://gift-edu.ru/wp-content/plugins/super-forms/uploads/php/files/93a489222059a1faf7a68a480cffd00a/donebabujemozuzawatuzin.pdfIn PDF document text
    • http://dotbamboo.com/file_media/file_image/file/giwidi.pdfIn PDF document text
    • http://dichvugiayphep.biz/upload/ck/files/nupaxop.pdfIn PDF document text
    • http://hebammenglueck.de/ckfinder/userfiles/files/97464262064.pdfIn PDF document text
    • http://f-okinawa.com/img/tmp/files/51032297215.pdfIn PDF document text
    • http://sanzmendia.com/userfiles/files/65548436277.pdfIn PDF document text
    • https://namratalakhotia.com/userfiles/files/30290952746.pdfIn PDF document text
    • https://rsun.pro/admin/ckfinder/userfiles/files/zegesozinoxezanutoto.pdfIn PDF document text
    • http://giprozdraw.ru/ckfinder/userfiles/files/fabakojefewetoge.pdfIn PDF document text
    • http://www.nbrownies.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1613051f48c3e4---91329364870.pdfIn PDF document text
    • https://embassyinvietnam.com/webroot/img/files/44105646637.pdfIn PDF document text
    • http://intranet.uts.edu.co/portal/app/ckfinder/userfiles/files/84943426273.pdfIn PDF document text
    • http://easytravel63.ru/ckfinder/userfiles/files/79733595418.pdfIn PDF document text
    • https://fiberglasssupplydepot.com/userfiles/files/maxuwa.pdfIn PDF document text
    • https://ijpdua.com/contents/files/18487537645.pdfIn PDF document text
    • http://vip-cond.ru/userfiles/file/gukigijof.pdfIn PDF document text
    • http://ccsl.asia/files/7659516551.pdfIn PDF document text
    • https://mps-india.com/userfiles/files/tulodibap.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/zMnd8XtcwSM/uplcv?utm_term=formula+of+nth+term+in+arithmetic+sequencePDF 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_off0000eaed.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEAED 10824 bytes
SHA-256: f8ccd15c1558ac59cd2283000464b3d23104f557da3e8e4a8b0ef3631087cbeb
font_01_sfnt_off000103b1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x103B1 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00011bc3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11BC3 19656 bytes
SHA-256: 9cda942c89bc841b2bfc0a87b1059f2e5f7a3d347e7e031208f2d7dd56a25b90