Malicious PDF — malware analysis report

Static analysis result for SHA-256 b50cfa71a89bda8a…

MALICIOUS

PDF

84.6 KB Created: 2021-09-18 16:04:30 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 8f8d23d2d4583292ebcfb55148f91b03 SHA-1: 72ade26e62ba0db52d0b33e4a06235efaf385656 SHA-256: b50cfa71a89bda8a77007f313f8c34649ed691e88108cd6d73fd541cbe894b49
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF containing embedded JavaScript, which is a common technique for executing malicious code. The PDF also features a link farm pointing to compromised WordPress uploads and disposable hosting, indicating an attempt to obscure the final malicious destination. The ML classifier and ClamAV detection strongly suggest malicious intent, likely phishing or malware delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

Heuristics 7

  • 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.
  • 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 http://ptaki.info/imgekoprojekty/files/57255542075.pdf
    • https://galerieportelouise.be/userfiles/files/72368440113.pdf
    • http://maxitelt.no/wp-content/plugins/formcraft/file-upload/server/content/files/1612fb9cd00602---jipelimoxusiparew.pdf
    • http://uitetenindex.nl/images/uploads/ruxukexo.pdf
    • https://www.sensormaticltd.com/app/templates/js/ckfinder/userfiles/files/wazolezulamivum.pdf
    • http://polletnv.be/uploads/files/moxagugoginekalelenujobuj.pdf
    • http://yuseigachi.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1613e0fd9e0872---64405594276.pdf
    • https://www.formwork.co.uk/wp-content/plugins/super-forms/uploads/php/files/f9earirr0j06kemg1lna8da0iv/lumetobu.pdf
    • https://doluhosting.com/calisma2/files/uploads/8976221383.pdf
    • http://marta-galan.com/files/varios/file/84818641855.pdf
    • https://apexforestservices.com/wp-content/plugins/formcraft/file-upload/server/content/files/16138bb8c984a3---42421417506.pdf
    • http://insuralead.com/userfiles/file/fimiretupivizamisonu.pdf
    • http://www.cheapmotorcycleinsurancepa.com/wp-content/plugins/super-forms/uploads/php/files/d7d0a4351d6cd3dfad79c41d63a21479/29795312302.pdf
    • http://fongyoskert.hu/userfiles/files/sokabonuwafawisupe.pdf
    • http://otohyundaidanang.com/uploads/image/files/15351285481.pdf
    • http://sushibelovo.ru/files/88870128129.pdf
    • http://festivaldeliteraturadepereira.com/wp-content/plugins/formcraft/file-upload/server/content/files/161394ed79af4f---vafuzabujaxewonudetabi.pdf
    • http://sushikyototogo.com/uploads/files/63060173482.pdf
    • http://rejs2013.cycling-recycling.eu/imgturysta/files/wowalivubulada.pdf
    • http://identik.hu/editor_up/33829763658.pdf
    • http://griesvoegwerken.nl/UserFiles/file/5145327013.pdf
    • http://bertrandetgastineaudesigners.com/userfiles/file/52622945825.pdf
    • https://vibangthuaphatlai.net/uploads/files/87138077302.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/3vuEKuznOb8/uplcv?utm_term=biology+books+for+class+11+samacheer+kalvi
    • 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_off0000db6f.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xDB6F 16792 bytes
font_01_sfnt_off0000f381.bin
b430d2a343f49c2753a515ece66d84f11bf5a5774a66eb01c19cb89d03e4f8bf
pdf-font-stream PDF embedded font (sfnt) at offset 0xF381 21552 bytes
font_02_sfnt_off000128ad.bin
8f7008e2441a7655a07bcc736771fd64a4a28c6f95c3ec71e310de6c20bd212e
pdf-font-stream PDF embedded font (sfnt) at offset 0x128AD 11100 bytes