Malicious PDF — malware analysis report

Static analysis result for SHA-256 bb7a73d32367af99…

MALICIOUS

PDF

85.7 KB Created: 2021-07-14 00:04:42 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: ce20e9986443977927b4ea1e2b09943c SHA-1: 783a7168b79d75ef0d94d321f7f124785b4d6bf4 SHA-256: bb7a73d32367af99a61c3dab3f8b98312ae53eb15afb1a5bddb51d046eadb347
104 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript and a large number of external URIs, many of which point to compromised CMS upload directories. The ML classifier strongly indicates maliciousness. The embedded JavaScript likely facilitates the redirection to these malicious sites, which are designed to host further malicious content or phish for credentials.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

Heuristics 6

  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://protech.com.ng/wp-content/plugins/formcraft/file-upload/server/content/files/160d8d9482124b---rufunakozifomu.pdf
    • http://lbs.ac.at/wp-content/plugins/super-forms/uploads/php/files/sng3obnnvb59d4u8b6nedbnv5o/tukes.pdf
    • https://fietenhaardenenkachels.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1607bc7a87fdca---81475391560.pdf
    • https://ms01bet.net/contents//files/bisidu.pdf
    • http://aeskulap24h.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a26549bdd9e---2472733747.pdf
    • http://bazis-expertiza.ru/ckfinder/core/connector/php/files/75489262464.pdf
    • https://fellowpeo.com/wp-content/plugins/super-forms/uploads/php/files/79906b5ed8fc58c92232c5fe9c6a2c66/tosugamudokare.pdf
    • https://aldea.work/wp-content/plugins/super-forms/uploads/php/files/dfb89c17070167bd2ba2cade9dff80a8/xinukuwulipijavif.pdf
    • http://vekosgroup.ru/userfiles/file/rudemajil.pdf
    • http://www.bandungmesin.com/file/pisevikegokuxumi.pdf
    • http://meyanko.com/userfiles/file///fiboxuzigevim.pdf
    • http://jjmcp.jp/userfiles/Image/file/63886029899.pdf
    • http://marasintl.com/public/ckfinderuploads/files/63014552911.pdf
    • http://synagoge-stommeln.de/ckfinder/userfiles/files/56598286003.pdf
    • https://cananalimdar.com/wp-content/plugins/super-forms/uploads/php/files/du6qtdciob4ukrilbeh4vj4clc/13797941831.pdf
    • https://i-chat.tw/js/ckfinder/userfiles/files/54938053507.pdf
    • https://www.teppiche-waschen-hamburg.de/wp-content/plugins/formcraft/file-upload/server/content/files/16071f464707c0---fivobopuwunatusanadire.pdf
    • https://alexandrapanayotou.com/web/images/static/file/28536686712.pdf
    • http://www.brennholz-heinlein.de/wp-content/plugins/formcraft/file-upload/server/content/files/160836f07bb7ad---jaduvomefuto.pdf
    • https://vuaship.com/wp-content/plugins/super-forms/uploads/php/files/es53tqha3cgenfn262can0ls65/gijewabarixojififobumu.pdf
    • https://adm.allianceflooring.net/wp-content/plugins/super-forms/uploads/php/files/5a014349091f76bce9a14fab895d66f0/jurabunarefixalupogedusor.pdf
    • https://xn--64-mlcufjjaii0l.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/996570da966a48c79440bb4d5a606dfd/95450382610.pdf
    • http://reszke.pl/fckeditor/editor/filemanager/connectors/php/file/31229905792.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/BkSY9tpko7c/uplcv?utm_term=internal+audit+is+conducted+by+mcq
    • http://kioskcondoweb.wpengine.com/wp-content/plugins/formcraft/file-upload/server/content/files/16074cb3da81bf---nuzevopariwinimafi.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_off0000eeab.bin
505272d786fe74783f0624addd3911489eea1c42942659f73f4508c7206e171b
pdf-font-stream PDF embedded font (sfnt) at offset 0xEEAB 16316 bytes
font_01_sfnt_off00011813.bin
3e52a9a293b040899c2b315e6bf1ba648d3a2cfe1abf51f69ae991064b28c8c5
pdf-font-stream PDF embedded font (sfnt) at offset 0x11813 10980 bytes
font_02_sfnt_off0001315e.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x1315E 16792 bytes