Malicious PDF — malware analysis report

Static analysis result for SHA-256 a9ed797b1bfa5f4d…

MALICIOUS

PDF

70.8 KB Created: 2021-09-26 12:57:16 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 0dd14aa834db6e13f59d24fc6bebc23b SHA-1: d84a37d034b2ad4359ada767bb9980c743a882a3 SHA-256: a9ed797b1bfa5f4d88bd7060d5082c24575603c78f93985b36f959411e59ce66
134 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1190 Exploit Public-Facing Application

The PDF contains embedded JavaScript and numerous external URIs, many of which point to disposable hosting. Heuristics indicate it functions as a link farm and is flagged by ML classifiers and ClamAV as malicious phishing content. The embedded JavaScript likely facilitates the redirection to these external sites, which are designed to deceive users.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9916

Heuristics 6

  • 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.
  • 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://philabc.ru/uplcv?utm_term=taxi+sim+2020+apk+mod
    • http://vako.vn/app/webroot/uploads/files/4428248907.pdf
    • http://ildong.org/sa_upload/userfiles/file/20210917204832.pdf
    • https://adamant54.ru/userfiles/files/razugelawiw.pdf
    • https://cli-kh.com/uploads/files/202109121505102564.pdf
    • https://cylinder96.ru/admin/ckfinder/userfiles/files/99524200624.pdf
    • http://metamorfoza-krosno.pl/userfiles/file/83739367408.pdf
    • http://www.cda.org.hk/ckfinder/userfiles/files/93469035701.pdf
    • http://yuanhebiotech.com/upload/files/xided.pdf
    • http://rakkhunnursinghome.com/user_img/files/2796450430.pdf
    • http://www.temaricerca.com/entry2013/admin/ckfinder/userfiles/files/lexugojujafi.pdf
    • http://npas.ru/pic/file/40053995197.pdf
    • http://www.catedralirodahaz.hu/data/editorfile/56581809840.pdf
    • http://sbsinternationalschool.org/userfiles/file/gosiko.pdf
    • http://musclecar-taps.com/js/upload/files/29015475492.pdf
    • http://thegioioto.store/upload/files/3704066149.pdf
    • http://geometrarontani.it/userfiles/files/wuduvaxow.pdf
    • http://househouse.it/userfiles/files/55753918901.pdf
    • https://www.bakkersvlaanderen.be/resources/plugins/ckfinder/userfiles/0/files/97952320118.pdf
    • http://ooexperience.be/assets/Image/files/49573254500.pdf
    • http://airsoft1.ro/files/file/nugetipolimavex.pdf
    • https://www.projectorrentals.com/wp-content/plugins/formcraft/file-upload/server/content/files/16140c2d0691ed---32705513557.pdf
    • http://hanhthien.net/uploads/file/73455868636.pdf
    • http://festivaldeliteraturadepereira.com/wp-content/plugins/formcraft/file-upload/server/content/files/161489376b04ef---kanaguxapafuralunarimos.pdf
    • http://hondatayho.top/img-ngocbao/files/6430819577.pdf
    • http://neuroxl.com/images/file/19602002762.pdf
    • http://travellerisland.com/files/9675707141.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_off0000b561.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xB561 16792 bytes
font_01_sfnt_off0000cd73.bin
f48275e24abce06d0287f179567f06a23e89db71095263e9e3b8d56d0857b9bc
pdf-font-stream PDF embedded font (sfnt) at offset 0xCD73 15980 bytes
font_02_sfnt_off0000f591.bin
c446ae0d09f574e7485c120b2305f4f8e58cc4407d17a662e5e4b5518391d5fc
pdf-font-stream PDF embedded font (sfnt) at offset 0xF591 10472 bytes