Malicious PDF — malware analysis report

Static analysis result for SHA-256 646e13c5573d2cae…

MALICIOUS

PDF

85.0 KB Created: 2021-06-29 04:00:32 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: e65c8f21b4cdf67ad090bc08492203f1 SHA-1: 613448a3c0bf3d7f92318d02706a566d395d963f SHA-256: 646e13c5573d2caea89ce17d881b54b35ff660917d079e6a2ece0d59fe2e5a94
96 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF file was flagged by an ML classifier as malicious. Static analysis revealed it functions as a link farm, containing numerous URLs pointing to various websites, some of which are hosted on compromised CMS platforms. The presence of these links suggests an attempt to direct users to potentially malicious or deceptive content, possibly for SEO manipulation or to host further stages of an attack.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9956

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://grupo-bahia-real-estate.com/ckfinder/userfiles/files/42658838084.pdf
    • https://majorsagilekvaros.hu/uploads/file/16111944135.pdf
    • https://izharfoster.com/wp-content/plugins/formcraft/file-upload/server/content/files/160949a550969d---siweforolusumifunaw.pdf
    • https://makiriaszto.hu/ckfinder/userfiles/files/nijazuranamoj.pdf
    • https://cbdc.co/uploads/ckfinder/userfiles/files/pudupubujejow.pdf
    • http://counterreaction.net/wp-content/plugins/formcraft/file-upload/server/content/files/1606d331bc437d---7038560340.pdf
    • http://aep-tc.com/cache/fck_files/file/43383192491.pdf
    • https://diarch.in/WYSIWYGImage/file/setegixem.pdf
    • https://srldirect.com/ckfinder/userfiles/files/82282376363.pdf
    • http://expertsystemgroup.com/file_media/file_image/file/18183398164.pdf
    • http://asalsold.com/wp-content/plugins/formcraft/file-upload/server/content/files/16074648f335e9---37683181106.pdf
    • https://www.energetisch-therapeut-estie.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1607ad3e779cbb---riseronefexuw.pdf
    • http://www.highlandmetals.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/16071ab71f28c7---16868722054.pdf
    • https://admonks.ru/wp-content/plugins/super-forms/uploads/php/files/672b1dda0207f2e54d67f2085c9b742a/wogikefedebu.pdf
    • https://puertoestereo.com/wp-content/plugins/super-forms/uploads/php/files/djic4t61kuslp5bfej85nl14d9/27840428869.pdf
    • https://bellevuecommunityfoodbank.org/wp-content/plugins/super-forms/uploads/php/files/342ddec2f021fb16f575c044fb1d390c/fonifawononosewoni.pdf
    • http://www.hptindia.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a9d4ffe80ab---sogudipilaveku.pdf
    • http://themultifold.com/wp-content/plugins/super-forms/uploads/php/files/l07siictgen4pj406bg2v5ehj3/94979844806.pdf
    • http://www.rpv-drachten.nl/files/file/samulatazufo.pdf
    • http://cgt-fo-csc.fr/wp-content/plugins/formcraft/file-upload/server/content/files/160a24544a3df8---31583197141.pdf
    • http://yjccnc.com/upload/files/2126558575.pdf
    • http://cavusofis.com/images_upload/files/99178248649.pdf
    • https://bawwabatrizq.com/userfiles/file/13608116894.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/A3Ryygt5BCM/uplcv?utm_term=rutherford+model+postulates
    • 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_off0000eb19.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xEB19 16792 bytes
font_01_sfnt_off00010330.bin
30ed87ff4a7afa55bb4936dad58325430cf40cebc1df679f01de1da6752d079a
pdf-font-stream PDF embedded font (sfnt) at offset 0x10330 10712 bytes
font_02_sfnt_off00011bd3.bin
037905411dba49ef71661d356fca9c92d3b02099f53b6b59faf485dc19cf5bd4
pdf-font-stream PDF embedded font (sfnt) at offset 0x11BD3 16688 bytes