Malicious PDF — malware analysis report

Static analysis result for SHA-256 cb05a1cdac5362a6…

MALICIOUS

PDF

78.7 KB Created: 2021-07-24 15:58:37 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 0c7de0b8229a07f8f85af2d0928572d2 SHA-1: 7bf780c0d5b01b4daa456cddb800d5969839cecb SHA-256: cb05a1cdac5362a6095554fc5e81b3f9369b39e14c81f68829e4be45477176f5
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF file detected by ClamAV as a phishing trojan. It contains embedded JavaScript, which is often used to exploit PDF vulnerabilities or redirect users to malicious sites. The presence of multiple links pointing to disposable hosting and compromised CMS uploads suggests a link farm designed to obscure the final malicious destination.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9949

Heuristics 7

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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 https://dafelia.com/files/47122567902.pdf
    • https://www.certificagreen.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c43f21f20ce---famixosunuxoziwibebog.pdf
    • https://wotfiles.com/ckfinder/userfiles/files/teravikozogusu.pdf
    • http://www.inhd.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160a81b097c751---79411364695.pdf
    • http://gold-carsales.com/js/upload/files/soruperufitojuxomore.pdf
    • http://1960vonsteuben.com/clients/d/df/dfb5e1b83ea85bfdc5ef1da934264264/File/nufowu.pdf
    • https://edukiya.com/wp-content/plugins/super-forms/uploads/php/files/8e36935f243bf8191c10d8917998356a/manojatixavobutoja.pdf
    • http://xn--80aafkqcanfpgnhbng3b5i9a.xn--p1ai/pict/file/jumubowutisuvan.pdf
    • https://zifu-tech.com/app/webroot/userfiles/files/migagatimoletad.pdf
    • http://www.nbrownies.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/16076963fc1042---817877729.pdf
    • http://scantech3d.com/files/bebulajome.pdf
    • http://www.recetasyconsejos.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c9b62727512---61322851162.pdf
    • http://anhuifan.com/upload_fck/file/2021-5-16/20210516153324474331.pdf
    • https://amerismithenterprises.com/wp-content/plugins/super-forms/uploads/php/files/ab3c67c8cb9c50e91adba87c6f9c4940/fukusitadeziparixodata.pdf
    • http://jagodkaprzedszkole.pl/userfiles/file/netomifadexofamomedupi.pdf
    • http://maskaevlawyer.ru/userfiles/file/66473023776.pdf
    • http://szyldkj.com/luodan/images/userfiles/file/77132219555.pdf
    • http://zabradli-znerezu.cz/userfiles/file/62011346602.pdf
    • https://assurancemauricie.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606d6ca1f3a21---kuxapave.pdf
    • http://call.ae/wp-content/plugins/formcraft/file-upload/server/content/files/160ba62a624e8c---midamitugorewipijowit.pdf
    • https://omomediacion.com/wp-content/plugins/super-forms/uploads/php/files/9b8a6001006e5a6c3d65ffed14573051/seduninigijuvidamekuxow.pdf
    • http://elijasprojekts.lv/files/file/84744310377.pdf
    • https://encouragingmath.com/wp-content/plugins/super-forms/uploads/php/files/3d4a7e39bf41833a9f3b33865738b456/jazaxoromapumiwegora.pdf
    • http://gorisum.net/fckeditor/upload_file/file/mebifubaxezuwuf.pdf
    • https://girilawfirm.com/content_files/files/74888398711.pdf
    • http://jeyadhurgatemple.com/userfiles/file/nuzikuwuduvaponajutabefeb.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/YTWXjIUwRh0/uplcv?utm_term=pokemon+all+episodes+in+tamil+dubbed
    • 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_off0000cfd6.bin
e258aa54d4b7d3d333d56b3d15338007cea12d75a854b2104233d104d59105dd
pdf-font-stream PDF embedded font (sfnt) at offset 0xCFD6 10784 bytes
font_01_sfnt_off0000e86d.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xE86D 16792 bytes
font_02_sfnt_off0001007f.bin
bc73ece1649e5e68f2ea50d74ac1a933fd04eca233bd0db73a90e5852c4b7ec8
pdf-font-stream PDF embedded font (sfnt) at offset 0x1007F 16968 bytes