Malicious PDF — malware analysis report

Static analysis result for SHA-256 81292c50beea266f…

MALICIOUS

PDF

74.8 KB Created: 2021-08-27 23:16:08 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 90fc1c7aabcf96cb2a29a0336f6a3d6b SHA-1: d87ae03703a908a38fcd46ee3bd87dd060c6d93b SHA-256: 81292c50beea266fb3028e5371213e44f851a94f72a2b2e83e0c4ac037cfe857
196 Risk Score

Malware Insights

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

This PDF file was detected as malicious by ClamAV and an ML classifier. It contains numerous links to external resources, many of which are hosted on compromised WordPress sites or disposable domains, suggesting an attempt to redirect users to download further malicious content. The presence of PDF_RANDOM_URL_LINK and PDF_SEO_DISPOSABLE_LINK_FARM heuristics indicates a pattern of using such links for distribution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9992

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 to algorithmically-generated URL high PDF_RANDOM_URL_LINK
    PDF contains a clickable HTTP(S) link whose host looks algorithmically generated (pronounceable-random labels) and whose path/query carries a long high-entropy token. This is the randomized-redirector pattern of malspam phishing lures — the visible document is only a prompt — not a PDF parser vulnerability.
  • 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://thamdinhgiadaiquang.com/img/files/579659948.pdf In PDF document text
    • https://bluetact.com/locktactyuma/userfiles/file/mutirezemubinupagi.pdfIn PDF document text
    • http://www.belladermeestetica.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1609c98aeec6f0---27493655010.pdfIn PDF document text
    • http://mobydick-band.de/fckdata/file/wukupam.pdfIn PDF document text
    • https://www.getfitcrew.com/wp-content/plugins/formcraft/file-upload/server/content/files/161172a29a3f5d---tosefifumifemugomotuji.pdfIn PDF document text
    • https://thehamptonsbloomington.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608c9d9fb6098---bowakejobatedewitif.pdfIn PDF document text
    • https://gbagencement.fr/uploads/file/75753314954.pdfIn PDF document text
    • http://isdoor.ru/uploads/files/358958045.pdfIn PDF document text
    • http://zartmobilia.com/userfiles/file/20210530080637.pdfIn PDF document text
    • https://glass-haus.ru/wp-content/plugins/super-forms/uploads/php/files/c585e7fd5a60a3f704b573310e23b69b/97706586359.pdfIn PDF document text
    • https://esz.jp/img/editor/files/kuwikowe.pdfIn PDF document text
    • https://loskutova.site/wp-content/plugins/super-forms/uploads/php/files/316b93e874f4c534c645898b316b1600/fexogad.pdfIn PDF document text
    • http://hengtongrongshang.com/jingkelun/userfiles/files/20210725000341.pdfIn PDF document text
    • http://szguilong.com/userfiles/files/zubetorojojubuponol.pdfIn PDF document text
    • http://thuephotocopytaihanoi.com/upload/files/98603971153.pdfIn PDF document text
    • https://dodomacnosti.net/data/file/nelipijaputuditapijuf.pdfIn PDF document text
    • http://sancheonglittletheaters.com/upload/userfiles/2021/06/files/210628111204.pdfIn PDF document text
    • http://mobilesamara.com/img/files/file/xolugawasuvubugerox.pdfIn PDF document text
    • http://lucidareemantenerepavimentifaidate.it/userfiles/files/89713744230.pdfIn PDF document text
    • https://foundryindia.org/userfiles/file/tawipunumawel.pdfIn PDF document text
    • https://www.reachcast.ca/wp-content/plugins/super-forms/uploads/php/files/f513ff152d7a341cb6c284f2a55eb872/17603373823.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/cv9VXjIrmdE/uplcv?utm_term=if+you+want+to+be+a+good+girlPDF link annotation
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#In PDF document text
    • http://purl.org/dc/elements/1.1/In PDF document text
    • http://ns.adobe.com/pdf/1.3/In PDF document text
    • http://ns.adobe.com/xap/1.0/In PDF document text
    • http://ns.adobe.com/xap/1.0/mm/In PDF document text
    • http://ns.adobe.com/xap/1.0/rights/In PDF document text
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000c2f3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC2F3 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000db0a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDB0A 10752 bytes
SHA-256: 6ee748f8938747e0ceca2b97c89b31499d82eecbffbd8e5f8b4a3b3d7ebd4f00
font_02_sfnt_off0000f3bb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF3BB 15856 bytes
SHA-256: e56edf9f0cd2b1fd10507ba8306a15098606d95f3e476ed0fa8d1cf314314b39

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