Malicious PDF — malware analysis report

Static analysis result for SHA-256 cbb6086097b16bca…

MALICIOUS

PDF

69.2 KB Created: 2021-09-24 14:50:38 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 3cee42fedc6161a27554e633958eb551 SHA-1: 14ca65faab8e304eef3b8946b83d74263bae2085 SHA-256: cbb6086097b16bca937525f4cefc1ed8973c2e167794390747d7230c325160ad
156 Risk Score

Malware Insights

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

The file is identified as malicious by ML classifiers and ClamAV, specifically flagged as a phishing trojan. Static analysis reveals it functions as a link farm, containing numerous URLs pointing to PDF files hosted on various domains, some of which are associated with compromised CMS uploads. The document body is heavily obfuscated and appears to be generated by wkhtmltopdf, suggesting it's not intended for direct user reading but rather as a container for 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://alatheir.com/atheirwsfiles/file/wujolosodabasobedefubir.pdf
    • http://bennett-legal.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/80197621066.pdf
    • http://italianopizzeria-pg.com/uploads/files/98645784868.pdf
    • http://ecosdaliberdade.com/ckfinder/userfiles/files/45721178970.pdf
    • http://templeton.sk/userfiles/file/jojavasisaralufe.pdf
    • https://alexandrapanayotou.com/web/images/static/file/39633376315.pdf
    • http://xn--80aafmoni2biho.xn--p1ai/admin/ckfinder/userfiles/files/83757115142.pdf
    • https://sportsht.com/userfiles/file/54026491276.pdf
    • http://linkingpeople.info/userfiles/file/62576486267.pdf
    • https://amagi.la/wp-content/plugins/formcraft/file-upload/server/content/files/1613cedcbede79---xamosudujedeberipeloz.pdf
    • http://mesotects.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613ddc5c743b6---zijomutuva.pdf
    • http://alexandersorokolaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/58922246829.pdf
    • https://deepex.hu/hirek/files/90936993712.pdf
    • http://potya.com/felafekazokuw.pdf
    • http://atdawnwelift.com/userfiles/file/meselebi.pdf
    • http://twfindia.in/userfiles/files/64833821826.pdf
    • http://bigdoughpizza.com/uploads/files/jekevenel.pdf
    • http://uyaviation.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614564e398c92---89655958003.pdf
    • https://mayersoffice.com/userfiles/file/91486816874.pdf
    • http://hkalc.com/userfiles/depuvusivafoj.pdf
    • http://beetsom.com/PROGRAM_FCKeditor_UserFiles/file/16734690716147942b248c4.pdf
    • http://nanobubblevietnam.com/uploads/userfiles/file/9649441104.pdf
    • http://happyorderfood.com/uploads/files/19149994610.pdf
    • https://strategieb2b.com/userfiles/file/larow.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/Om9ozkHLxGw/uplcv?utm_term=maricaban+pasay+city+postal+code
    • 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_off0000af8f.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xAF8F 16792 bytes
font_01_sfnt_off0000c7a1.bin
d391d1182c74b2f9da5609a66add0555ca9aa1f0eda12810a79f2c8de0b47b3f
pdf-font-stream PDF embedded font (sfnt) at offset 0xC7A1 15508 bytes
font_02_sfnt_off0000eeb3.bin
e3ef75b21f5dc4c4de04175367af4a73c8019724a54d10d74dbaf4fd0586e980
pdf-font-stream PDF embedded font (sfnt) at offset 0xEEB3 10752 bytes