Malicious PDF — malware analysis report

Static analysis result for SHA-256 ae76f1031a679c80…

MALICIOUS

PDF

87.8 KB Created: 2021-08-26 06:06:39 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-22
MD5: 5eec2f36e7c015c90824cec3dbfdb775 SHA-1: 546f82793b8d9a5585cad43bb620fc5510feaf6d SHA-256: ae76f1031a679c80ef6302b9d2b30a4542421ebdedfec67ae213a848a8cc86bd
96 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs pointing to compromised WordPress sites and other disposable hosting. These URLs are likely used to host malicious content or redirect users to phishing pages. The ML classifier strongly indicates maliciousness, and the link farm structure suggests an attempt to distribute malware or phish for credentials.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9980

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://ketchas.ru/uplcv?utm_term=reference+letter+for+teacher+from+principal PDF link annotation
    • https://jennysbooks.com/wp-content/plugins/super-forms/uploads/php/files/8fa418ae41b67d7b9432a5565c94c819/sewiginexu.pdfIn PDF document text
    • https://svetpoznaniyaonline.ru/wp-content/plugins/super-forms/uploads/php/files/8a6733eb39d62597c0f80c1515e3ae81/9244043510.pdfIn PDF document text
    • http://kovove-ploty-brany-zabradli.cz/UserFiles/File/82469168731.pdfIn PDF document text
    • https://parc-hotel.info/file/76780006991.pdfIn PDF document text
    • https://regalcabs.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/160da464f345f1---tebefe.pdfIn PDF document text
    • http://langeline.com/ckeditor/upload/files/lewixezifelufujaf.pdfIn PDF document text
    • https://mytopics.it/uploads/file/8228627943.pdfIn PDF document text
    • http://poorclarescork.ie/images/26063652751.pdfIn PDF document text
    • http://doo-san.com/userfiles/file/20210510035500.pdfIn PDF document text
    • https://ankaratemizlikcim.com/depo/sayfaresim/file/luwaromuboxunanu.pdfIn PDF document text
    • http://kaufdeinauto.de/wp-content/plugins/formcraft/file-upload/server/content/files/1609d397441374---68423152731.pdfIn PDF document text
    • https://dadrarad.ro/userfiles/file/59750973707.pdfIn PDF document text
    • https://too.kg/wp-content/plugins/super-forms/uploads/php/files/6de0bb311e733dc0e17c0c7b891ac4f7/40419460968.pdfIn PDF document text
    • http://alexandraharris.com/clients/36054/File/11495853212.pdfIn PDF document text
    • https://afd.me.uk/wp-content/plugins/super-forms/uploads/php/files/rjlhrm0hpib7vqpig4ugbkhatc/dozikokerena.pdfIn PDF document text
    • http://www.kreasoft.mx/wp-content/plugins/formcraft/file-upload/server/content/files/160b12a1d8f104---38049803745.pdfIn PDF document text
    • https://amkboiler.com/wp-content/plugins/super-forms/uploads/php/files/23t560acus86gitlitca7io91a/mexenitizatowonexudupe.pdfIn PDF document text
    • https://kogan-photo.ru/wp-content/plugins/super-forms/uploads/php/files/fd945c90417c82e2f63f2683c25bf260/96111108687.pdfIn PDF document text
    • http://eshop-kocicinadeje.cz/files/file/valusosovaxefezerubujipa.pdfIn PDF document text
    • https://choiceenergynetwork.com/wp-content/plugins/super-forms/uploads/php/files/7d01ef4ce63708975e4acc2fc135a6b2/70773190774.pdfIn PDF document text
    • http://rajskiewakacje.pl/userfiles/file/108459331.pdfIn PDF document text
    • http://irodori.kir.jp/files/file/kugimusosesugoxikago.pdfIn PDF document text
    • 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_off0000f3b5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF3B5 17324 bytes
SHA-256: ced0a297c279c3978c5827d65866fd79b9392833778c4bbe19d8d1ffc2f7cd38
font_01_sfnt_off00012101.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12101 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00013918.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13918 10624 bytes
SHA-256: e0ddcdb487475dbb3275d68c148483d5096633175cf881ebb046a1718addaedd