Malicious PDF — malware analysis report

Static analysis result for SHA-256 7163e79472236b78…

MALICIOUS

PDF

70.3 KB Created: 2021-09-17 13:41:26 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: a547557214cbcc15eca1d89ba4b53179 SHA-1: 925b9d9406cd3a4069c07d93b02b144b8a75310f SHA-256: 7163e79472236b789add4b12d3bda18a746492a86f698f61e51189915b6e47d6
156 Risk Score

Malware Insights

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

The PDF file was identified as malicious by ClamAV and an ML classifier, exhibiting characteristics of a link farm. It contains numerous external URIs, with several pointing to compromised CMS upload directories, suggesting an attempt to lure users to malicious content. The document body is heavily obfuscated and unreadable, providing no direct clues to its intent beyond the heuristic findings.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9947

Heuristics 6

  • 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.
  • 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://china-glass-mosaic.com/userfiles/files/20210906_235217.pdf
    • http://grupophi.es/uploads/files/lewetivosividiburomumuwa.pdf
    • http://daydeothe.vn/rich_editor/file/81503855814.pdf
    • http://kursadowicz.pl/Upload/file/ranodabegi.pdf
    • https://inverpalmas.com/aym_image/files/jotepegigudemezasiniwof.pdf
    • http://thuocnam.xyz/images/files/wetuduzumemipokupuvivub.pdf
    • http://www.holderit.com/wp-content/plugins/formcraft/file-upload/server/content/files/161405b6d23ac9---joditadomutewoxusomew.pdf
    • http://agilesolutions.in/uploads/92381530697.pdf
    • http://zkojicin.cz/userfiles/file/xurileluvolunosufake.pdf
    • http://gamboeng.com/assets/ckfinder/userfiles/files/19411090339.pdf
    • http://synergyproperty.com/images/files/73366710314.pdf
    • http://loca-granderoue-montaletang.com/ckfinder/userfiles/files/widutem.pdf
    • http://syarmarka.ru/userfiles/files/misakekubojez.pdf
    • http://stomerijindex.nl/images/uploads/17196572833.pdf
    • http://cobansut.com/userfiles/file/79908577691.pdf
    • http://musorcentrum.hu/files/article/file/99795198559.pdf
    • http://aow.infogestnet.it/ckfinder/userfiles/files/74009138742.pdf
    • http://runhouchem.com/upload/files/bopajomipeb.pdf
    • http://extreamtuning.ru/wp-content/plugins/formcraft/file-upload/server/content/files/161410b6a7078a---fupepixip.pdf
    • https://markzone.az/wp-content/plugins/super-forms/uploads/php/files/hluos0feh91h5t6cdvato1ge89/28385846552.pdf
    • http://ghefoot.com/fckeditor_userfiles/file/37922871766.pdf
    • https://hamasataccessories.com/userfiles/files/37109329035.pdf
    • https://jamurgoreng.net/contents/files/8139956839.pdf
    • http://xn--80aiddhbkcq5bcaz.xn--p1ai/upload/files/ragavotudu.pdf
    • http://stellarvvv.ru/ckfinder/userfiles/files/95393104438.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/YTWXjIUwRh0/uplcv?utm_term=download+j2me+games+for+android
    • 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_off0000b4b1.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xB4B1 16792 bytes
font_01_sfnt_off0000ccc3.bin
86a091a656ff7c72d297b7f8d9dce490299eb0dcf7fbafbf6abfb11d15fa448f
pdf-font-stream PDF embedded font (sfnt) at offset 0xCCC3 14976 bytes
font_02_sfnt_off0000f2ab.bin
e4dab980e39385a81b4d4329d868eac87eadcae2e1e3e6841cbaf4acc77924ae
pdf-font-stream PDF embedded font (sfnt) at offset 0xF2AB 10936 bytes