Malicious PDF — malware analysis report

Static analysis result for SHA-256 a4e23addc8a3e0b1…

MALICIOUS

PDF

85.6 KB Created: 2021-09-13 12:32:19 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 392b6577b7615e53ed8ef91d800c5c2f SHA-1: 01bae5fc85bf11bbe02fd4beb41aff2261e18f96 SHA-256: a4e23addc8a3e0b157707616146f671d5a87386f43413c6ba4b6761d62daa4ac
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs that form a link farm, many pointing to compromised WordPress uploads or disposable hosting. Heuristics indicate this is a link farm designed to redirect users, and the ML classifier and ClamAV detection strongly suggest malicious intent, likely phishing or malware distribution. No scripts were extracted, but the PDF structure itself is used to host and distribute these malicious links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

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://laborke.ru/uplcv?utm_term=world+no+1+android+game+2020
    • http://cuacuonductudong.com/upload/files/56829997628.pdf
    • http://abwplazaview.com/uploads/files/vodake.pdf
    • http://absolutelyneon.com/userfiles/file/83016219833.pdf
    • https://derey.nl/app/webroot/files/userfiles/files/42945533113.pdf
    • http://liga-stf.ru/i/upload/files/sikime.pdf
    • http://csc-0898.com/userfiles/file/20210902090132_eskg42.pdf
    • http://erulingua.hu/uploads/content_files/files/83374141940.pdf
    • https://blsautomation.com/ckfinder/userfiles/files/89804584196.pdf
    • https://bursaceviritercume.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613a6e827043f---xijexufilixaj.pdf
    • http://meadescafe.com/userfiles/file/95690899162.pdf
    • https://majorsagilekvaros.hu/uploads/file/71841200327.pdf
    • https://kitchensofdiablo.com/upload/file/79493884781.pdf
    • https://xn--80apefbdm9ah5g.xn--p1ai/userfiles/jowigix.pdf
    • http://zehanbiopharma.com/upload/files/lowakeletomo.pdf
    • https://sealordhotels.com/ckfinder/userfiles/files/57849763300.pdf
    • http://alfavs.eu/userfiles/file/basopinim.pdf
    • http://www.cargeacrew.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1613b9d2a1e6e9---fipulogikimakajamulepum.pdf
    • https://bbensonmft.com/wp-content/plugins/super-forms/uploads/php/files/dd81831cbef0470d3524af47607d7143/88224233610.pdf
    • https://tvsporedi.si/vsebina/51139509885.pdf
    • https://omnistopbollards.com/application/third_party/ckfinder/userfiles/files/48809067773.pdf
    • http://jewelry-shopping-city.com/uploads/files/202109051757582792.pdf
    • https://www.restaurant-latableedevercel.com/ckfinder/userfiles/files/66606429206.pdf
    • http://abpjseah.news-read.com/upload/files/tozipatubatodaxuraredafov.pdf
    • http://reyazahmad.bscsaoner.in/ckfinder/userfiles/files/tazevopigurinofudi.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_off0000ec35.bin
76d54b2175d2107f3cf42e0b8d1c0643303d94b36320da15d0fd8a464c594866
pdf-font-stream PDF embedded font (sfnt) at offset 0xEC35 10612 bytes
font_01_sfnt_off00010446.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x10446 16792 bytes
font_02_sfnt_off00011c58.bin
696a70b2adfef3cd674877b20b8a9453bd7a651b25a988b395bbe9439f076c59
pdf-font-stream PDF embedded font (sfnt) at offset 0x11C58 17200 bytes