Malicious PDF — malware analysis report

Static analysis result for SHA-256 237e381b787989ba…

MALICIOUS

PDF

76.6 KB Created: 2021-09-11 18:43:41 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: e9ea4d9b8dbc005aa454979e2a93988d SHA-1: 436bbd968255e8ee39a465a787d451123ec72074 SHA-256: 237e381b787989bab72f027e4c068dad520946c7d46246f025dd090922861495
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF file was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. It contains a link farm with numerous URLs, many pointing to potentially compromised websites or disposable hosting, designed to redirect users to download files. The presence of multiple PDF link farm heuristics indicates a deliberate effort to obscure the final destination and increase the chances of a successful lure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9980

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://allora-tour.by/var/upload/file/66017552277.pdf In PDF document text
    • http://jamalcar.com/userfiles/file/javugoziguxaz.pdfIn PDF document text
    • http://drivingschool-brno.eu/files/56253070577.pdfIn PDF document text
    • https://gpuhub.net/wp-content/plugins/super-forms/uploads/php/files/i8f2fqur5vt9vl4ulm3u5or8cb/57281468657.pdfIn PDF document text
    • https://skyzoan.com/cake/beta/userfiles/file/vujapaxonevemejoz.pdfIn PDF document text
    • http://dtyxbpzx.com/filespath/files/20210909054741.pdfIn PDF document text
    • http://unityproductions.com/upload/files/69341293221.pdfIn PDF document text
    • https://webmodels.studio/wp-content/plugins/formcraft/file-upload/server/content/files/1612f5db10ed50---40492500397.pdfIn PDF document text
    • http://lgassociates.in/uploads/27403199565.pdfIn PDF document text
    • http://www.ibadirect.com/wp-content/plugins/formcraft/file-upload/server/content/files/16139b9b9a0f8e---94360030472.pdfIn PDF document text
    • http://zjleiou.com/images/upload/File/48205994095.pdfIn PDF document text
    • http://aadcnfgl.netsociality.com/upload/files/kozugeverubiragogonigotud.pdfIn PDF document text
    • https://kiptep.ru/file/89508260960.pdfIn PDF document text
    • http://casier-a-bouteilles.fr/file/60176918309.pdfIn PDF document text
    • https://tinhhoaxanh.vn/userfiles/file/wedowufer.pdfIn PDF document text
    • https://postelezmasivu-liberec.cz/ckfinder/userfiles/files/zizovenofibikit.pdfIn PDF document text
    • http://embody.box8websites.com/ckfinder/userfiles/files/87131910209.pdfIn PDF document text
    • https://basealimentare.it/webroot/files/fck_uploads/File/15098498761.pdfIn PDF document text
    • http://aire-limpio.com/img/editor/file/65817659728.pdfIn PDF document text
    • https://onecre.com/images/content/files/94176541694.pdfIn PDF document text
    • http://xn--90ad5ackt1d.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/835cb0f40f8562e8b44641315ecce4f9/22098301050.pdfIn PDF document text
    • https://pinkrali.com/calisma2/files/uploads/wodoxilabawekul.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/PmAiG5ZyT-k/uplcv?utm_term=cricket+19+mod+apk+downloadPDF 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_off0000c61e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC61E 10936 bytes
SHA-256: c1950664a345ed9295ed53b752b65c70c59d71d65145619506a2be5b70d7e9cd
font_01_sfnt_off0000df9b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDF9B 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000f7ad.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF7AD 17496 bytes
SHA-256: 80e626aa0fa18d9bec2caa30e24a5de36942fe8891481f89aa085982d8c4bb1c