Malicious PDF — malware analysis report

Static analysis result for SHA-256 d77e2ba87a6663dc…

MALICIOUS

PDF

80.3 KB Created: 2021-08-01 03:18:20 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: d5a7679c20e32e53aa06144222886521 SHA-1: 2d52681662fa3a25b25140cdbb70e8bbc84bcb68 SHA-256: d77e2ba87a6663dc269537d283df5b4ff5f647b46f57ccf44bac85e0758e5dee
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF file contains numerous links to external PDFs hosted on various websites, many of which appear to be compromised or disposable. The ClamAV detection and ML classifier strongly indicate malicious intent, likely for phishing or distributing further malware. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' confirms the nature of the document as a link farm.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9996

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 http://bjaimama.com/data/upload/2021/07/file/202107170858118660.pdf
    • http://wildzipper.com/clients/wildzipper/userfiles/file/46605076908.pdf
    • http://ohappy.org/userData/board/file/15541194625.pdf
    • https://chongtham68.com/app/webroot/uploads/files/pugixigilejoroxuxexuvut.pdf
    • http://www.peopleoftheheath.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a361d6ab57e---30404035475.pdf
    • http://classicalgardenornaments.com/uplds/file/gijalukonisuboridafake.pdf
    • https://koffiewarenhuis.nl/app/webroot/files/userfiles/files/41891565304.pdf
    • http://veronicanealhome.com/wp-content/plugins/formcraft/file-upload/server/content/files/2/160ddbcac82ef5---48980545038.pdf
    • http://www.holzbau-hoelzl.at/wp-content/plugins/formcraft/file-upload/server/content/files/160b01a813846d---61148672558.pdf
    • https://bnovum.hu/downloads/fajimifamatanupe.pdf
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609cd313b33ce---17997303349.pdf
    • http://win-sonic.com/kida2018/ck_imgs/files/83497729746.pdf
    • http://schouteninterieurwerk.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1607a0aa79bfec---75678390604.pdf
    • https://www.yoursurveysurveyors.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/16083a7e801ac7---xutudalomivofobebimivev.pdf
    • https://www.projectorrentals.com/wp-content/plugins/formcraft/file-upload/server/content/files/160e4aef5f41b7---63247032369.pdf
    • http://nanoscopy.ru/uploads/files/lalifagatasu.pdf
    • http://vinmexindia.com/uploads/zuvif.pdf
    • https://praward.tw/wp-content/plugins/super-forms/uploads/php/files/3da293e11a0e3567b88c9efd9bfd712d/zumuzatimajerader.pdf
    • http://ff-engineering.com/userfiles/files/98008651008.pdf
    • https://kvkumariajnkvv.org/singhania/downloads/file/zidefizut.pdf
    • http://www.benvenutialmare.com/wp-content/plugins/formcraft/file-upload/server/content/files/16074bf01a7b9f---jusisoxa.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/GLLx1DTH0VQ/uplcv?utm_term=gce+o+level+timetable+2016
    • 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_off0000d7c3.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xD7C3 16792 bytes
font_01_sfnt_off0000efd5.bin
112157a97988a1556563372686b91abece65a62ac23fb9b3918585b23e18722f
pdf-font-stream PDF embedded font (sfnt) at offset 0xEFD5 16500 bytes
font_02_sfnt_off00011ad2.bin
4a7d180b9a44bceac912919aa983cfffbb399c9ed3e3dcd4ed50c5c989d28311
pdf-font-stream PDF embedded font (sfnt) at offset 0x11AD2 10724 bytes