Malicious PDF — malware analysis report

Static analysis result for SHA-256 d8af8bf3a8857356…

MALICIOUS

PDF

89.3 KB Created: 2021-07-07 23:26:18 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 891d405b1c380f02c605e54b51c52919 SHA-1: 0077916b9fc8db84f2226f4ddfa04da6717bd9b8 SHA-256: d8af8bf3a885735607393a91c7da6183ecc4c839a95411fe41357ac77f567563
96 Risk Score

Malware Insights

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

The PDF contains a large number of external links, many of which point to PDF files hosted on compromised CMS upload directories or disposable domains. This behavior is indicative of a link farm, potentially used for SEO poisoning or to distribute further malicious content. The ML classifier strongly flagged this PDF as malicious, supporting the assessment of a malicious intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9947

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://szabobuszrendeles.hu/files/files/52530101841.pdf
    • http://litho-and-co.fr/ckeditor/upload/files/tabovexofajaru.pdf
    • https://ispartaorganizasyon.com/ckfinder/upload/files/57995567224.pdf
    • http://www.danvillern.com/wp-content/plugins/super-forms/uploads/php/files/dg2bo3mdq92gfbi0aca6scer63/pawabadutopubefevomofaf.pdf
    • http://mu-rrrc.com/userfiles/file/dijazexi.pdf
    • http://vegasoft.hr/wp-content/plugins/formcraft/file-upload/server/content/files/160b9cc762de98---30142905819.pdf
    • http://kirakuramenandsushi.com/uploads/files/32432521985.pdf
    • https://trouver-une-ssii.com/img/pics/files/pavawumuxerepukomotiguli.pdf
    • https://bywuf.org/upload/editor/files/21303044604.pdf
    • http://pinturasoltra.com/images/slider/files/93705768871.pdf
    • http://xn--dlek-5qa.com/admin/UserFiles/file/66198202101.pdf
    • http://atdawnwelift.com/userfiles/file/98199939706.pdf
    • http://vudafrique.com/wp-content/plugins/super-forms/uploads/php/files/0e794863a8b66adb7ceca89ca28e6504/76340780283.pdf
    • http://www.absolutecateringla.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bd7ba74b30c---83381809201.pdf
    • http://studiobonvino.com/userfiles/files/15707681890.pdf
    • http://penzionklara.cz/userfiles/file/fadenoku.pdf
    • http://www.tobywells.org/media/fckdir/file/96612641440.pdf
    • https://eandjfamilyhealthcenter.com/wp-content/plugins/super-forms/uploads/php/files/a0543714b60fb6826487e0c13103d1a9/zojawopetapinobixavovifa.pdf
    • http://webinaris.net/ckfinder/userfiles/publics/files/tebafimikawaxarabuxa.pdf
    • https://cobrawire.com/userfiles/files/41966205852.pdf
    • http://www.pianoszimmermann.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160a701d8e60bc---makirawef.pdf
    • http://ljhalls.com/wp-content/plugins/super-forms/uploads/php/files/d2a480e0d1244e87ecbd384314944854/77533256424.pdf
    • http://capitalclassof1970.com/clients/e/e7/e78cae7b17622b0161c193cbd63f4fd0/File/3624200184.pdf
    • http://poorclarescork.ie/images/sovubirogasi.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/BvfzZFkJO3s/uplcv?utm_term=bryonia+30+used+for
    • 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_off0000f6d5.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xF6D5 16792 bytes
font_01_sfnt_off00010ee7.bin
dafda098a135ce10009b26fa548829ebaac173901651df0f570c4aecbbbb6a16
pdf-font-stream PDF embedded font (sfnt) at offset 0x10EE7 17816 bytes
font_02_sfnt_off00013db4.bin
330de5e28a82bad9905dd9b1b2fbefd77051a6f47d93ce671927455e9614f1fd
pdf-font-stream PDF embedded font (sfnt) at offset 0x13DB4 10764 bytes