Malicious PDF — malware analysis report

Static analysis result for SHA-256 a457757a49b6deb5…

MALICIOUS

PDF

71.1 KB Created: 2021-09-28 20:46:59 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 4e13f344cddb34e8cdb4b0d3399e2d90 SHA-1: d1677acc8fb09c1b722db5676c3672601fc21437 SHA-256: a457757a49b6deb54ae20fe8181f56ce99c2386f4c55756403bf1badb6354994
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was flagged by ClamAV as a phishing trojan and a machine learning classifier indicated maliciousness with high confidence. It contains numerous external URIs and a link farm pointing to various domains, suggesting an attempt to redirect users to malicious content. Embedded JavaScript was also detected, which could be used to facilitate these redirects or further exploit the user.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9956

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.
  • 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://pistant.ru/uplcv?utm_term=pubg+android+wallpaper
    • http://newworldss.com/uploads/file/wixuvafiwegizovezap.pdf
    • http://majortaylorride.info/images/uploaded/file/85992330125.pdf
    • http://getdol.com/page_data/file/6710924117.pdf
    • https://cms.blauraum.com/wp-content/plugins/super-forms/uploads/php/files/700d8cdd2bdb75a9dea3dddc75c538f7/masifizurewesok.pdf
    • http://fuerst-architects.com/uploads/file/8683481322.pdf
    • http://park-seversk.ru/other/js/ckfinder/userfiles/files/pevakalukati.pdf
    • http://verynailscm.com/user_img/file/bodepori.pdf
    • http://camberwelltaxi.com/survey/userfiles/files/kazabifunubilawaz.pdf
    • http://zulassung4you.de/bilder/file/jimosamikofenofe.pdf
    • https://phoenixknights.co.uk/wp-content/plugins/super-forms/uploads/php/files/bd99e40e7c5d457d4a66b762ee777f3a/25839813798.pdf
    • http://oookub.ru/upload/fckeditor/file/32295857713.pdf
    • https://regenerateacademy.com/file/kapusizuvut.pdf
    • https://ahirealty.in/admin/userfiles/files/fikikowoxumurikarag.pdf
    • http://helloslow.com/data/userfiles/files/deraronisidas.pdf
    • http://propertiesforrent.com/userfiles/file///joremegonutamasadapupazi.pdf
    • http://florylaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/29835739910.pdf
    • http://jamoncup.es/wp-content/plugins/formcraft/file-upload/server/content/files/161344262de1a2---xejeligozakaxusexas.pdf
    • https://www.penyembuhanholistikreiki.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614835747095f---57045134113.pdf
    • https://klingende-zeder.de/wp-content/plugins/formcraft/file-upload/server/content/files/1615022ac823ff---81381838142.pdf
    • http://synagoge-stommeln.de/ckfinder/userfiles/files/68469296791.pdf
    • https://argekaucuk.com/nbg/upload/files/ruwuboteruna.pdf
    • http://dogable.de/userfiles/file/3014801886.pdf
    • https://loctra.net/userfiles/file/fozuvesubugaxu.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_off0000b13d.bin
7ff62a69b2350e10b00e793219132d2f7fe6e68c851a391477f4248f29ffdfbb
pdf-font-stream PDF embedded font (sfnt) at offset 0xB13D 17792 bytes
font_01_sfnt_off0000df38.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xDF38 16792 bytes
font_02_sfnt_off0000f74f.bin
4ebc9370a2d44565123287aa6731e6ebf2083ad9d6d56414745a3108e739e37b
pdf-font-stream PDF embedded font (sfnt) at offset 0xF74F 10628 bytes