Malicious PDF — malware analysis report

Static analysis result for SHA-256 f31e45f2df5fa271…

MALICIOUS

PDF

82.1 KB Created: 2021-06-26 00:34:05 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: a06594af769b57b059da8c3ef0347988 SHA-1: a049f4a1bf164b72161bac80b951c758ff4b37b4 SHA-256: f31e45f2df5fa2711ffe2cd9454b6e31f782ad53ad522ce8cc79cb1aa41088c1
196 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous links pointing to compromised WordPress sites, likely serving as a link farm to distribute malicious content. The ClamAV detection and ML classifier strongly indicate malicious intent, specifically a phishing or trojan distribution campaign. While no scripts were explicitly extracted, the PDF structure and URL patterns are consistent with attempts to redirect users to malicious payloads.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9946

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 https://investainternational.com/wp-content/plugins/formcraft/file-upload/server/content/files/16092a79bea4d7---wipizafuzokarevitije.pdf
    • https://pfgmm.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/160b37a4161130---7037481036.pdf
    • https://ambulatorioveterinariosismondi.eu/file/26298682674.pdf
    • https://aimara-bg.com/userfiles/file/vilitumozadakexa.pdf
    • https://pensionatiitalianiinportogallo.it/wp-content/plugins/super-forms/uploads/php/files/72ecebc7fa4356e820522bb602af397f/wusijetovubakaruf.pdf
    • http://trenermichal.pl/wp-content/plugins/formcraft/file-upload/server/content/files/160bd7784295f3---sovivavubejuw.pdf
    • https://gfow.om/wp-content/plugins/super-forms/uploads/php/files/kum082e9pspuo5ubn8unn3jber/45450012582.pdf
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/160cf2b30189e5---43235727949.pdf
    • http://szyldkj.com/luodan/images/userfiles/file/89416438772.pdf
    • http://serendipityorlando.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609ccef51d383---zojadumivibozotira.pdf
    • http://adanateknikservis.web.tr/wp-content/plugins/formcraft/file-upload/server/content/files/160bb6b8faba3f---kutepojolokozibibidi.pdf
    • http://nova-auto.com/upload/76102711480.pdf
    • http://nutricion-intravenosa.com/wp-content/plugins/super-forms/uploads/php/files/e299207d0c98ba7dd723c96c5120fbf5/25000736651.pdf
    • https://lightspec.ca/wp-content/plugins/super-forms/uploads/php/files/6b15cccd1f9c9ec9566742ec4f6d9d73/popuziputigavute.pdf
    • http://cutencuddlybreedables.com/_images/file/61577894874.pdf
    • http://tulga.ru/editor/files/tibilisuzukadirok.pdf
    • http://mko-yug.ru/wp-content/plugins/super-forms/uploads/php/files/eaafda6940102eba87f67c7da33a3dc6/43668554843.pdf
    • https://underworldgear.com/upload/users/files/losuwef.pdf
    • http://rideco.hu/upload/file/17162601071.pdf
    • https://blugarden.eu/file/66153442519.pdf
    • http://reiki-roots.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/16083968b178a3---gewizidak.pdf
    • https://gulertrafik.com/wp-content/plugins/super-forms/uploads/php/files/3rn1gbl3ukpb9d0sujei2judbs/62719373220.pdf
    • https://remoteworkerclub.com/wp-content/plugins/super-forms/uploads/php/files/fe2060bd6e67d7788998f7de5ec51df9/povajemefonowezogij.pdf
    • http://bagandpack.ru/wp-content/plugins/super-forms/uploads/php/files/efc5d0ac0fd8ba1d34aabf5465011d8d/dibal.pdf
    • https://maisonforville.be/documents/file/78488259518.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/GLLx1DTH0VQ/uplcv?utm_term=the+sphere+of+silence+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_off0000de40.bin
ce59b7375f3d2145ded32dd06b5b5f4d3ad957bca84fa2493a5b60f10c726c29
pdf-font-stream PDF embedded font (sfnt) at offset 0xDE40 10420 bytes
font_01_sfnt_off0000f5b5.bin
3c701f161640978b4ac51f318a41994c55bf5f1a443659ad20f9e0160d334d0a
pdf-font-stream PDF embedded font (sfnt) at offset 0xF5B5 16816 bytes
font_02_sfnt_off00012159.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x12159 16792 bytes