Malicious PDF — malware analysis report

Static analysis result for SHA-256 e5f51d4926983399…

MALICIOUS

PDF

69.3 KB Created: 2021-09-28 20:37:21 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: c10e3825db7d10a21936fb95987e536c SHA-1: 59cb043439d39beb014b7b7525fa30b690090aa3 SHA-256: e5f51d4926983399e587eb5da830a818c45314787f884065492f72a5ffd14570
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample was flagged by ML and ClamAV as malicious, specifically as a phishing trojan. It contains embedded JavaScript and a large number of external URIs, many of which point to compromised WordPress sites or disposable hosting, forming a link farm. The embedded JavaScript likely facilitates the redirection to these malicious sites, which are designed to lure users into downloading further malware or divulging sensitive information.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9916

Heuristics 7

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://irlanc.ru/uplcv?utm_term=android+phone+speed+test
    • http://phongthuydotho.vn/upload/files/94831505724.pdf
    • http://halongbaycruises.org/upload/files/tozosedebo.pdf
    • https://www.generalutilities.com/wp-content/plugins/formcraft/file-upload/server/content/files/16138779d039aa---2242358541.pdf
    • https://motecx.com/images/file/9003155238.pdf
    • http://srtprogetti.eu/userfiles/files/mozokoturidodoj.pdf
    • https://aayams.com/userfiles/file/janakoxexal.pdf
    • http://yoga-privates.com/yoga-privates/file/68968141856.pdf
    • http://studioguidobarbieri.it/userfiles/files/tilanoluwuxanawikuki.pdf
    • https://aukshanya.promosing.com/alpha/ckfinder/userfiles/files/43229592969.pdf
    • https://exam11.menapoint.com/app/webroot/upload/files/24919922545.pdf
    • http://titibbs.xyz/js/ckfinder/userfiles/files/toziji.pdf
    • http://ptairsupply.com/userfiles/file/wewosezofaniru.pdf
    • https://matras-matrasych96.ru/admin/ckfinder/userfiles/files/bejukewiriju.pdf
    • http://shimamura-mail-order.com/userfiles/file/3311594798.pdf
    • https://floridainvestment.cz/files/file/72148774358.pdf
    • https://divetechmarine.com/contents/files/364432074.pdf
    • http://0225674989.kad.tw/kads/ckfinder/userfiles/files/87681303597.pdf
    • https://biomedchita.ru/imeg_master/file/581495836.pdf
    • http://entone.es/wp-content/plugins/super-forms/uploads/php/files/c1068fe7998cce43165dc121987480ef/81379514840.pdf
    • http://ural-resyrs.ru/data/file/58571179815.pdf
    • http://slowjamsundays.com/wp-content/plugins/formcraft/file-upload/server/content/files/16137da81e5961---64378774209.pdf
    • https://danfort.lv/userfiles/file/4610151137.pdf
    • http://omni-links-europe.com/images/blog/file/wubagadipogitabidos.pdf
    • http://inspeq.eu/public/files/morunup.pdf
    • http://rayer.cn/d/files/rovexukipejefunu.pdf
    • http://tele-klass.ru/i/upload/files/sowekasupogagovakaroteve.pdf
    • 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_off0000b3bf.bin
ab1e51d89f236c248b4e6c629035c4aec917f98d4fd2db3a68ac2b4a38bd07ed
pdf-font-stream PDF embedded font (sfnt) at offset 0xB3BF 10260 bytes
font_01_sfnt_off0000cabc.bin
ee5a7e279982d3f0c07b2b9b552413dce73ac31ff0b004f23918a27d825dd4dc
pdf-font-stream PDF embedded font (sfnt) at offset 0xCABC 14640 bytes
font_02_sfnt_off0000ef56.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xEF56 16792 bytes