Malicious PDF — malware analysis report

Static analysis result for SHA-256 b72013904fce5391…

MALICIOUS

PDF

81.3 KB Created: 2021-09-07 11:55:56 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 5ea98816265c1eb2d6a5f64c817b3332 SHA-1: 720a96abbd5962cd424260162bef84a505af0d40 SHA-256: b72013904fce539115e39b69656868b59a5b1b3ca6353ba6b55f47452af1073c
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. The PDF contains numerous external URIs, many pointing to compromised CMS upload storage or disposable hosting, suggesting a link farm designed to redirect users to malicious content. The presence of embedded URLs and the nature of the heuristics strongly suggest this PDF is used as a lure for phishing or to distribute further malware.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://krisoc.ru/uplcv?utm_term=short+story+animal+farm+pdf
    • https://rrvchefs.com/wp-content/plugins/super-forms/uploads/php/files/04f3f7383c12ee23130480eaa3b86649/70813087868.pdf
    • http://jljemc.com/upload/files/tonemuxefifuxenu.pdf
    • http://kennyre.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607f3663f05d4---64692326680.pdf
    • https://traveletrust.com/basefile/traveletrustcom/files/23794687700.pdf
    • http://topopentertainment.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c3e2dcaedb4---gujitipaza.pdf
    • http://firstcuwire.com/file_media/file_image/file/zewozef.pdf
    • http://articolo17.it/siti//usr/foto/files/lozoji.pdf
    • https://volpatoebrum.com.br/_common/admin/scripts/ckfinder/userfiles/files/88914664193.pdf
    • http://cnex.cc/images/blog//file/16814286161.pdf
    • http://kochamsushi.pl/UserFiles/file/zobinubeg.pdf
    • https://ontime-taxi.kg/wp-content/plugins/super-forms/uploads/php/files/a4bd4fccb9dc2be3bb084443b1ae92b4/88617077341.pdf
    • https://webhostmurah.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609c66b3566bc---karewixedo.pdf
    • https://www.lowdoc-loans.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/160c3d8d6d5839---fapusaf.pdf
    • http://stkvn.ru/wp-content/plugins/super-forms/uploads/php/files/48b32f7ed72b488333a381cccaf973aa/97627720864.pdf
    • https://www.temsilcisitesi.com/wp-content/plugins/formcraft/file-upload/server/content/files/16083eb2b4dc3c---fexofebikulalidot.pdf
    • http://kimwendelldesign.com/ckfinder/userfiles/files/mavovoxel.pdf
    • https://conberraquera.com/aym_image/files/61429597041.pdf
    • http://ipmarketing.net/userfiles/file/xedesudobusenirosubaxita.pdf
    • https://www.booster-p.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608efb2ec8a08---nulim.pdf
    • http://www.giuseppe.ru/ckfinder/userfiles/files/mopaligiz.pdf
    • http://themultifold.com/wp-content/plugins/super-forms/uploads/php/files/7j46rj9g0kc28n7j29e9ug2co7/xikizixedalupabosufeluti.pdf
    • https://www.hintonassociates.com/wp-content/plugins/super-forms/uploads/php/files/ad854a39c140362b2a3f58944f80cd7c/mugobemosolejetokot.pdf
    • https://ultralloy.net/upload/files/28209715214.pdf
    • https://spherule.org/wp-content/plugins/super-forms/uploads/php/files/41541bcea8019966b436ba8a604bd9de/28983702697.pdf
    • https://brahmagnanam.org/fck_uploads/file/rezijunuretoz.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_off0000d853.bin
27f7cefc0354120e2d895a83a511345c1d951b8b6c99eb26d7b2f73f020aa873
pdf-font-stream PDF embedded font (sfnt) at offset 0xD853 10820 bytes
font_01_sfnt_off0000f10c.bin
cac79f87d0035252ffae173e04264e02ed48255d4a562d882dfa4ec42622e9a6
pdf-font-stream PDF embedded font (sfnt) at offset 0xF10C 17844 bytes
font_02_sfnt_off00011f4e.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x11F4E 16792 bytes