Malicious PDF — malware analysis report

Static analysis result for SHA-256 317a4a9353a129d2…

MALICIOUS

PDF

70.6 KB Created: 2021-09-16 10:56:20 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 795f93db67156cc1b55a27ca6fc811a1 SHA-1: f978041b5ea24a7b09cb60db963882e68bc083e2 SHA-256: 317a4a9353a129d2d39ee7bfe8ed38015973c63af4598bda21a71f339b0e2c98
96 Risk Score

Malware Insights

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

The PDF file contains a link farm that redirects to multiple PDF files hosted on various domains, some of which appear to be compromised CMS uploads. The presence of a 'utm_term=download free psiphon for android' URL suggests a lure for users seeking specific software, likely leading to malware. The ML classifier also strongly indicated maliciousness.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9909

Heuristics 5

  • 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://huntic.ru/uplcv?utm_term=download+free+psiphon+for+android
    • http://daegyung.kr/userfiles/file/20210910013609.pdf
    • http://andersonlawdecorah.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/86559291979.pdf
    • http://www.ctmmaximoravenna.com/ckfinder/userfiles/files/845746509.pdf
    • http://cheniou.handysociality.com/upload/files/loporuzutobij.pdf
    • https://avis-medical.ma/wp-content/plugins/super-forms/uploads/php/files/3eebd9851b57593bfe994715f3526d39/65017871083.pdf
    • http://naturpix.ch/cmsimages/file/7062262344.pdf
    • http://insureavisitor.com/userfiles/file/bagokibapulakes.pdf
    • http://notariocprietoa.com/notaria/documentos/files/86947338946.pdf
    • http://akinmedikal.com/uploads/file/50602763022.pdf
    • http://www.singchai.co.th/ckfinder/userfiles/files/87636369083.pdf
    • http://studioagm.it/userfiles/files/zewuvadamova.pdf
    • https://beautydiction.com/ckfinder/userfiles/files/32828215529.pdf
    • http://ckm-machinery.com/userfiles/files/60844148379.pdf
    • http://discarga.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613f1118a8578---xopeduzi.pdf
    • http://www.satit.nrru.ac.th/satit/_Adminis/ckfinder/userfiles/files/38385792229.pdf
    • http://k12kos.com/ckfinder/userfiles/files/54039291870.pdf
    • https://10playsolutions.com/clients/softklk/documents/_articles_/file/52989186797.pdf
    • http://osullivanspressurewashing.com/wp-content/plugins/formcraft/file-upload/server/content/files/161396bac1cd25---kunajozosajupivowuzow.pdf
    • https://sealskinz.ru/files/file/renirevunudenadogazinu.pdf
    • http://ewtch.com/upload/files/76700141855.pdf
    • http://gma.ge/admin/ckeditor/ckfinder/userfiles/files/zofapekisew.pdf
    • https://muzpony.de/obrazki/file/12546334782.pdf
    • http://netflor.pl/upload/File/dubewised.pdf
    • https://carcarnet.com/home/sandbox/domains/hkdance.tritek.hk/public_html/ckfinder/userfiles/files/delupawa.pdf
    • https://careerroots.net/ckfinder/userfiles/files/nurafafoziwujikizibuvos.pdf
    • https://webhostmurah.com/wp-content/plugins/formcraft/file-upload/server/content/files/16133d65dc5e36---50488247835.pdf
    • https://www.borzabadi.com/ckfinder/userfiles/files/62205005598.pdf
    • http://www.cpiequipos.com/assets/images/user_files/files/zosudigixukaxe.pdf
    • 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_off0000b738.bin
355a8f12411ef237a04b8c71d7f3baa696031091c5614ee45a4ee67722c1e181
pdf-font-stream PDF embedded font (sfnt) at offset 0xB738 14812 bytes
font_01_sfnt_off0000dbea.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xDBEA 16792 bytes
font_02_sfnt_off0000f401.bin
c9e071f81fc9db954f8e1bfceb4675c814e5cfea110d9a8a4d88bb8f166f1867
pdf-font-stream PDF embedded font (sfnt) at offset 0xF401 10584 bytes