Malicious PDF — malware analysis report

Static analysis result for SHA-256 4a4c528608ff0dde…

MALICIOUS

PDF

80.9 KB Created: 2021-09-06 17:25:47 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: cb02b2e009e8665711df01aa23b39492 SHA-1: c8a1cb19d669e30ea5c3f344f6b4095e52ea6cbf SHA-256: 4a4c528608ff0dde76590459208684664c46047bb663a77532c649997a25f6c3
96 Risk Score

Malware Insights

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

The PDF contains numerous links, many pointing to compromised CMS uploads and disposable hosting, suggesting a link farm designed for SEO manipulation or to distribute further malicious content. The ML classifier strongly indicated maliciousness, and the structure aligns with techniques used to host or redirect to malicious payloads.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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://pphu-joanna.pl/fckpliki/file/zebidimaratekenirojupisal.pdf
    • http://belovosushi.ru/files/51045179966.pdf
    • https://jclifeschools.org/wp-content/plugins/super-forms/uploads/php/files/4e5a566672a1985d5a0f378acd3fdb77/77739370291.pdf
    • http://envisystem.com/upload/userfile/files/zarefatiguzizakonego.pdf
    • http://www.saraviation.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607d61bf7ff6e---gigowakovoledewumuxoz.pdf
    • https://cmfnepal.org/userfiles/files/72099566374.pdf
    • https://allcreaturesinc.com/files/files/16666227823.pdf
    • http://www.nuricomuvakfi.org/wp-content/plugins/super-forms/uploads/php/files/vse9q23mvh14ts9eufpg3288h7/71574900186.pdf
    • http://maciejabramowicz.pl/upload/files/file/5464332394.pdf
    • https://saikekanglun.com/filespath/files/20210819123037.pdf
    • http://www.ponderosafestival.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613081837e91a---56326674450.pdf
    • https://www.golddustdental.com/wp-content/plugins/formcraft/file-upload/server/content/files/160f6b2ce8557e---15397893075.pdf
    • https://www.swx.global/wp-content/plugins/super-forms/uploads/php/files/2295340ff59adb0f747b312d7c10d86a/bewewibumakoxudevi.pdf
    • https://karapinarinsaat.net/userfiles/upload/file/91582352044.pdf
    • https://deewo.de/wp-content/plugins/formcraft/file-upload/server/content/files/16102b3c4db264---59189428549.pdf
    • http://vegasoft.hr/wp-content/plugins/formcraft/file-upload/server/content/files/16106ef881a19e---83911842392.pdf
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609d8fc73dcec---biwudovukiviwixedow.pdf
    • https://asset-books.com/userfiles/file/49564728523.pdf
    • https://laurallo.com/ckfinder/userfiles/files/modisas.pdf
    • http://www.dfdtrading.sk/ckfinder/userfiles/files/bovafonelugusijolip.pdf
    • http://hattrick-sports.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bbb26212c3d---43482136175.pdf
    • http://soupworld.de/upload/file/limepon.pdf
    • http://math-talk.kr/wp-content/plugins/super-forms/uploads/php/files/uq8lf7n2jes7bfhtfutgah0gog/waxunobowarexil.pdf
    • https://arizonapoolcontractor.com/wp-content/plugins/formcraft/file-upload/server/content/files/16091a059258dd---koxukivaforutam.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/6naE_Nh8_CY/uplcv?utm_term=sindrome+de+glanzmann+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_off0000d06b.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xD06B 16792 bytes
font_01_sfnt_off0000e882.bin
e0dbd2360b1924f1feee010642ffc3b3695acca732263bab1f744c217646b8dd
pdf-font-stream PDF embedded font (sfnt) at offset 0xE882 10712 bytes
font_02_sfnt_off000100d6.bin
86c5de1de2058f67ee15e9bc8c4750bc33998bc71d5c9bf33200f03084dd6704
pdf-font-stream PDF embedded font (sfnt) at offset 0x100D6 20624 bytes