Malicious PDF — malware analysis report

Static analysis result for SHA-256 9523999a7e274a2d…

MALICIOUS

PDF

88.0 KB Created: 2021-08-25 05:35:15 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: b7f2c961a1a11be32d2779a9f7051edd SHA-1: e9d0acd4cfd929353627d4db25ebd237ebb740f1 SHA-256: 9523999a7e274a2d05fd47a1872b00f62068f3dcdcb25dc93227ad52625964aa
96 Risk Score

Malware Insights

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

The PDF contains a link farm pointing to numerous distinct hosts, many of which appear to be compromised WordPress sites utilizing the Formcraft plugin for file uploads. The ML classifier strongly indicated maliciousness, and the structure suggests an attempt to manipulate search engine rankings or distribute payloads via these compromised sites. No scripts were extracted, limiting the analysis of direct execution vectors.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9991

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 http://prodesign31.ru/wp-content/plugins/formcraft/file-upload/server/content/files/1608f141130a3d---42132288645.pdf In PDF document text
    • https://afmiletisim.com/resimler/files/fezuguzetasurajugaxere.pdfIn PDF document text
    • https://nenmongdangquang.com/upload/files/42638661473.pdfIn PDF document text
    • https://maconlux.lu/userfiles/files/remetezoguditewi.pdfIn PDF document text
    • http://careerhack.net/wp-content/plugins/formcraft/file-upload/server/content/files/160985635045e3---6375919169.pdfIn PDF document text
    • https://swotin.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a74db40a3d9---34435161058.pdfIn PDF document text
    • http://automotiveenergy.cz/userfiles/file/72211755826.pdfIn PDF document text
    • http://henri-ruch.ch/doc_pub/file/70980675444.pdfIn PDF document text
    • http://hk-keber.de/images/file/66774114268.pdfIn PDF document text
    • https://www.helpforbusymums.com/wp-content/plugins/super-forms/uploads/php/files/12b4d2f10f67d0a2d15220c1fa16d2e4/jibedisoxosegutadusi.pdfIn PDF document text
    • http://training-solutions.ro/wp-content/plugins/formcraft/file-upload/server/content/files/161140efe35573---941980438.pdfIn PDF document text
    • https://gift-edu.ru/wp-content/plugins/super-forms/uploads/php/files/ba869f152f1049f6b4acafe87dee577e/tekagizavukak.pdfIn PDF document text
    • https://markzone.az/wp-content/plugins/super-forms/uploads/php/files/s0kdjlrhliaob3ou651o3iln38/50670293399.pdfIn PDF document text
    • http://www.adanakursmerkezi.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ade1afa6400---59490378076.pdfIn PDF document text
    • http://btfa.tw/upload/files/mepenanimu.pdfIn PDF document text
    • http://www.fullmooneye.com/wp-content/plugins/formcraft/file-upload/server/content/files/160829825dfbb5---7654380479.pdfIn PDF document text
    • http://apsara.ru/userfiles/file/vurekigowavedibol.pdfIn PDF document text
    • http://ekonopuntos.com/campannas/file/88297795003.pdfIn PDF document text
    • https://www.karenlovelee.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606ca314156b6---45952191879.pdfIn PDF document text
    • http://grupomarsamo.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607650bbc16c2---2582950416.pdfIn PDF document text
    • http://alibabashipping.com/userfiles/file/sudijupobirakulavetope.pdfIn PDF document text
    • http://irmascaritasdejesus.org.br/wp-content/plugins/formcraft/file-upload/server/content/files/160839cfbaa952---jinoxupamat.pdfIn PDF document text
    • https://nhaban24h.com.vn/wp-content/plugins/super-forms/uploads/php/files/8v38eta40atlnjsu6tku801s43/92839702043.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/cv9VXjIrmdE/uplcv?utm_term=lalisa+manoban+latest+picturesPDF 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_off0000ec92.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEC92 20724 bytes
SHA-256: b2b5caa9f400348a9d4c37ef9bc5527ff5d9e9b07c78834155b2ccf41e7d7697
font_01_sfnt_off00012192.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12192 10732 bytes
SHA-256: 7bc35d5886bf6197fd21e100eb1d20244c550e210bbe47fb5ad0bbc78ce3beea
font_02_sfnt_off000139fb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x139FB 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1