Malicious PDF — malware analysis report

Static analysis result for SHA-256 91156ec1df83d4ea…

MALICIOUS

PDF

84.3 KB Created: 2021-08-19 20:55:51 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 7eaa3a19f40546da3e33419c243ad57c SHA-1: 7cc02d2d71d061351b3d693be1711a49e3277ec6 SHA-256: 91156ec1df83d4ea5aa697052a0ef5245941722db6f73a376d8862597fb8fee6
156 Risk Score

Malware Insights

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

The PDF file contains a large number of links, many pointing to compromised WordPress sites and disposable hosting, indicating it functions as a link farm. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or distributing further malware. The embedded URLs and link farm structure are indicative of an attempt to lure users to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9978

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://krisoc.ru/uplcv?utm_term=fast+and+furious+7+full+movie+in+hindi+hd+1080p+watch+download
    • https://aydin-elektrik.com/resimler/files/jenijurituginidudapaxemi.pdf
    • http://www.puhito.hu/uploads/93369331291.pdf
    • https://retentionstudentexperience.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a3b13e4a24d---nijosulokabagelavuf.pdf
    • https://hopefor.today/wp-content/plugins/super-forms/uploads/php/files/695c84e6d74334bf4ccab243b9f069f6/gaxixinodurutod.pdf
    • http://www.kindytennis.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609b84dc75930---82648013093.pdf
    • https://ailani.org/wp-content/plugins/super-forms/uploads/php/files/d3225c2a172ae76d3d06513e67d452b2/93628664959.pdf
    • http://alarcon-v.com/editor_upload_image/file/saboziwifevubuw.pdf
    • http://skrabl.pl/www/rpbd/fck/file/pofejugegijegiwatefeviga.pdf
    • https://sport-jicin.cz/dokumenty/sezopomolumimefunukusoru.pdf
    • https://intrigantka.ru/images/userfiles/file/muwaxuwewafupi.pdf
    • https://fultoys.com/userfiles/kozudogufogofunexite.pdf
    • http://www.klpreschool.com/wp-content/plugins/formcraft/file-upload/server/content/files/160963787380ee---desoxaxoduzasexawalined.pdf
    • https://srp-galabau-rostock.de/wp-content/plugins/super-forms/uploads/php/files/n40voqlnut6hk97r00hpkd35av/bubolorul.pdf
    • http://unseenadventure.com/userfiles/file/xupidivimipixafowedi.pdf
    • http://saydersan.com/firma/files/posevikejujatidunukivoso.pdf
    • https://www.htlexpress.com/ckfinder/userfiles/files/wokeruwabawuronagokeza.pdf
    • https://victory-agency.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a4b24b73320---39059462087.pdf
    • https://codecs.ro/images/file/59283735688.pdf
    • http://bridgesonthepark.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b42c10149df---xigodewevimemoverupixumi.pdf
    • http://swatimishra.in/uploaded_files/userfiles/files/90219446852.pdf
    • http://luingpyrex.cz/foto/Image/file/19558367.pdf
    • http://pvsystexperts.com/wp-content/plugins/super-forms/uploads/php/files/htragbq5g4g1ii0a11l3e2lem3/wopikotuvezejobed.pdf
    • http://fly.no1-yes.com/userfiles/file/fafan.pdf
    • https://travels-ukraine.com/wp-content/plugins/formcraft/file-upload/server/content/files/160e5d043c726b---75999481762.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_off0000e21c.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xE21C 16792 bytes
font_01_sfnt_off0000fa33.bin
dc731518b6936050a8936fe6f587eebe15a3d25999ded1fb7e41eb5542d94507
pdf-font-stream PDF embedded font (sfnt) at offset 0xFA33 11544 bytes
font_02_sfnt_off00011584.bin
32f8796fdf98ef670d528c81ce08d8cb11c2949c81abf4dcef65701f407777dc
pdf-font-stream PDF embedded font (sfnt) at offset 0x11584 17056 bytes