Malicious PDF — malware analysis report

Static analysis result for SHA-256 91e28e0b6af09d56…

MALICIOUS

PDF

86.9 KB Created: 2021-09-23 10:11:25 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 9e06ec340833c92809375232d7a59ae9 SHA-1: a0c08413f1f4145e4c47c1a0a4654caf551c6c3f SHA-256: 91e28e0b6af09d563efb6a2047908ca43a5f6038ca57cac4059ba06e32ce6235
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs, many of which point to compromised websites or disposable hosting, indicating a link farm designed for redirection. The ML classifier and ClamAV detection strongly suggest malicious intent, likely phishing or malware distribution. Although no scripts were explicitly extracted, the PDF structure and URL patterns are consistent with techniques used to deliver second-stage payloads or redirect users to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9905

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.
  • Visual download / call-to-action button lure low SE_DOWNLOAD_BUTTON
    Document contains a call-to-action phrase ('Click here to download', 'Download Now', etc.) — low-signal unless other findings point to a malicious workflow
  • 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://sysyanginguvenlik.com/uploads/files/fezariloti.pdf
    • https://www.fangjin.org/ckfinder/userfiles/files/11828906086.pdf
    • http://alexlunacoach.com/img/editor/file/82820744973.pdf
    • https://jdsliquorlocker.com/nbloom/fckuploads/file/40073544142.pdf
    • https://www.gml.de/wp-content/plugins/formcraft/file-upload/server/content/files/1612f19c86df7f---65827950760.pdf
    • https://bocrangsuthammy.vn/upload/files/fikekunu.pdf
    • http://daonshop.com/files/fckeditor/file/44878305202.pdf
    • http://esangsok.com/upfile/files/paxurebi.pdf
    • https://wanna-drive.nl/files/File/18945503038.pdf
    • https://razredna-nastava.net/files/buvolad.pdf
    • http://yatros.ro/wp-content/plugins/formcraft/file-upload/server/content/files/161478ba351b85---91824586794.pdf
    • http://pensionpoint.cz/userfiles/files/80569224583.pdf
    • http://iscelenie.info/files/file/50276251907.pdf
    • https://dubigroup.com/admin/fckeditor/editor/filemanager/connectors/upload/file/vobemun.pdf
    • http://skonasystems.com/userfiles/file/sidelabizinevabudiv.pdf
    • http://rutka.pl/media/upload/files/a37df5cceae1c31574a48692017ca7ad.pdf
    • http://autoscuolavalerio.it/userfiles/files/xekirisaxizeneked.pdf
    • https://olivier-daulte.com/ckfinder/userfiles/files/474064782.pdf
    • http://colafranceschi.it/userfiles/files/vogidurefiki.pdf
    • https://immsac.pe/sgi_userfiles/userfiles/files/mixanujululunoteka.pdf
    • http://cp-tournament.org/ckfinder/userfiles/files/41545300957.pdf
    • https://amesmedicalservices.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614475d91ffb6---wanebekazezo.pdf
    • http://vamaconsulting.sk/userfiles/file/14815505636.pdf
    • http://alpha-th.com/userfiles/file/zenofe.pdf
    • http://enotecagaribaldi.it/userfiles/files/47288136535.pdf
    • http://awarelaxcentrum.cz/user_files/file/48064961710.pdf
    • http://frangarcia.eu/upload/file/bokabajiso.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/GLLx1DTH0VQ/uplcv?utm_term=nimo+tv+apk+ios
    • 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_off0000e7ee.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xE7EE 16792 bytes
font_01_sfnt_off00010000.bin
fca08adfdc15383f3a2696acd064dcbf3cf49a4c964313b0ec018f6ad3258a33
pdf-font-stream PDF embedded font (sfnt) at offset 0x10000 20272 bytes
font_02_sfnt_off0001351a.bin
2b82655cd678f036c7fc96f2d8418527a2f5b22df6e90bc5ce251963a1984891
pdf-font-stream PDF embedded font (sfnt) at offset 0x1351A 10168 bytes