Malicious PDF — malware analysis report

Static analysis result for SHA-256 184c16019527b644…

MALICIOUS

PDF

84.9 KB Created: 2021-09-16 03:07:09 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 337fb6ba600d64a8ce7640810f795ff0 SHA-1: ebbb12ec3ad54142ad16987f540e0d9d104d0c0b SHA-256: 184c16019527b6443f70ffa08d726d525099d09dcaec6a351020403285d0ec8c
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. Heuristics indicate it functions as a link farm, directing users to multiple potentially compromised WordPress upload directories and other disposable hosting sites. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for 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://nuraski.pl/wsg/userfiles/17068168145.pdf
    • http://nagakuratrading.com/js/upload/files/meduveg.pdf
    • https://djhelaly.com/wp-content/plugins/super-forms/uploads/php/files/c27a7223e427b13802840fa68f4f3e66/nutogobobizesuligab.pdf
    • https://www.chortho.co.uk/wp-content/plugins/super-forms/uploads/php/files/fobd92mnl8h8ehhm32k24660r6/24674907625.pdf
    • https://bimore.vn/webroot/img/files/dagabijut.pdf
    • http://konikanarrowfab.com/ckfinder/userfiles/files/98154076703.pdf
    • https://deepex.hu/hirek/files/87559840261.pdf
    • https://marsanz.pl/uploads/fck/file/pomoxobotot.pdf
    • http://chiangmai-esc.net/user_img/files/tewerojepanixegopepate.pdf
    • http://sspvjd.com/FileData/ckfinder/files/20210905_6E27419541B34FA7.pdf
    • https://tunhuaduytan.com/upload/userfiles/files/letuvoladuzudol.pdf
    • https://thietbivesinhanhhuy.com/asset/files/76046401728.pdf
    • http://www.offshoreyachts.net/web_upload/editor/files/pakufutaligalet.pdf
    • http://sklenicky-obchod.cz/web/admin/fckeditor/userfiles/file/wenozipizigoman.pdf
    • http://suliaok.com/v15/Upload/file/202193949338154.pdf
    • https://edenestates.com/ckfinder/userfiles/files/22820235164.pdf
    • https://alkhairi.co.uk/wp-content/plugins/super-forms/uploads/php/files/b0e623e7429d47cafef55f3644c0fa79/9686297888.pdf
    • http://musiclivemarsala.com/userfiles/files/zonipolazorovugasafereri.pdf
    • http://goodwill.as/userfiles/file/98391823987.pdf
    • http://summitremodelinginc.com/userfiles/files/sudimipolib.pdf
    • http://aktifimmo.lu/userfiles/files/ximowujidaxurivudabamez.pdf
    • http://kechengchem.com/upload/files/78650921015.pdf
    • https://snf.styleguides.ch/userfiles/files/movimorutoregufola.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/A3Ryygt5BCM/uplcv?utm_term=meme+app+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_off0000ea59.bin
67212e4187f2eabae04ae7f5edd533759a20ef6745247059e639eee6c85fd1b5
pdf-font-stream PDF embedded font (sfnt) at offset 0xEA59 10340 bytes
font_01_sfnt_off00010196.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x10196 16792 bytes
font_02_sfnt_off000119a8.bin
e2b2940c92243b3ee5e503f6b94aeb7b9621e3cc3b878c73e097d7a157d52127
pdf-font-stream PDF embedded font (sfnt) at offset 0x119A8 17228 bytes