Malicious PDF — malware analysis report

Static analysis result for SHA-256 ec3fbdee18f5880f…

MALICIOUS

PDF

89.4 KB Created: 2021-06-25 14:36:56 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: d4155d165ce8114bbe20fc2695f1817e SHA-1: 06cb44021196d73901ab2fa6f41b36bc168af709 SHA-256: ec3fbdee18f5880ff43ea3bc7728d397d8e6a9a21d10b13aabdce23a46f8affd
196 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains multiple links to external URLs, many of which point to compromised WordPress sites used for hosting malicious content. The ML classifier and ClamAV detection strongly indicate malicious intent, likely to deliver a second-stage payload. The presence of PDF_RANDOM_URL_LINK and PDF_SEO_DISPOSABLE_LINK_FARM heuristics further supports the attack pattern of luring users to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9991

Heuristics 7

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://www.sunarnuricomuisvealisverismerkezi.com/wp-content/plugins/super-forms/uploads/php/files/has2ql3m3pv54usoiicl9hgf93/puxof.pdf
    • https://www.opdrrustukalac.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607ed7ade7fed---silibuwerodikigobamozarow.pdf
    • http://xn--9p4b29dncp2cc6y.net/upload/fckeditor/file/99949095043.pdf
    • https://klingende-zeder.de/wp-content/plugins/formcraft/file-upload/server/content/files/16077f81a919bc---71981287986.pdf
    • https://www.golaw.net/wp-content/plugins/formcraft/file-upload/server/content/files/160c46a7857359---xedujalokoronafenus.pdf
    • https://greyquotient.com/wp-content/plugins/super-forms/uploads/php/files/b90836bb4ad065d63d7c50e8e8611a64/mewomipugasonel.pdf
    • http://premiumresourcing.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609837d85dfc7---kidepan.pdf
    • https://xn--80aaa1anac6cg.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/825b2ae1b4403e821eb0024501bbb64f/texaf.pdf
    • http://esistore.be/userfiles/file/4652838403.pdf
    • http://www.bluewhaleline.com/image/upload/File/rejugugepoxalofufimufo.pdf
    • http://geoodwierty.pl/files/file/rakogumulepijinolikiwul.pdf
    • http://tsradviseurs.nl/mailing/images/photo/file/puzererosuxuzikikegopejin.pdf
    • http://whuntex.ru/userfiles/file/66216624394.pdf
    • https://agrilaui.com/userfiles/file/50701376651.pdf
    • http://www.putnamtaxi.net/wp-content/plugins/formcraft/file-upload/server/content/files/1608773f20a58b---gozelekabunokiliwodep.pdf
    • https://nationalcardsolutions.com/wp-content/plugins/formcraft/file-upload/server/content/files/160afefeb40e76---duropimejasisakasasifajip.pdf
    • https://kfz-gutachter-oliver-schiller.de/wp-content/plugins/formcraft/file-upload/server/content/files/160bcdbb3311e3---joniwewog.pdf
    • http://www.socalgreatwhite.com/wp-content/plugins/formcraft/file-upload/server/content/files/16092f07da7bd2---44922118842.pdf
    • http://omatsuri.kr/data/userfiles/files/mokuliximiragodog.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/A3Ryygt5BCM/uplcv?utm_term=summary+application+online
    • 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_off0000fad4.bin
4acbc350b4658f32a1cdc094482507916d4bcc995ee14d765dad528517c60ddc
pdf-font-stream PDF embedded font (sfnt) at offset 0xFAD4 17304 bytes
font_01_sfnt_off0001282b.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x1282B 16792 bytes
font_02_sfnt_off00014042.bin
f04e7b526304f8ba3e9013b87ef9d57bf2781d2dfda59d8b48eb94c8b933e8a2
pdf-font-stream PDF embedded font (sfnt) at offset 0x14042 10656 bytes