Malicious PDF — malware analysis report

Static analysis result for SHA-256 77a4d7a19479b880…

MALICIOUS

PDF

95.7 KB Created: 2021-08-03 18:43:38 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: fd033a0e34e02ff93e29b490bb790918 SHA-1: 04783584ad5f854d51f7b28255b9200d994ba372 SHA-256: 77a4d7a19479b880c8b831e58c269a3ba1afcb1cdbe149d920a2e6ec3d77f83a
156 Risk Score

Malware Insights

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

The PDF contains a large number of links, many pointing to compromised CMS upload directories or disposable hosting, indicating a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely phishing or malware distribution through these links. No scripts were extracted, but the structure and URL analysis are sufficient to determine the attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9996

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 http://netmode.net/app/webroot/uploads/files/gaderedojimanewo.pdf
    • http://eau-msu.ru/ckfinder/userfiles/files/biwavugoliduxufaduw.pdf
    • https://www.hdcorp.com.br/wp-content/plugins/super-forms/uploads/php/files/9lafmqq5sh45c5pkb6fjeiirgt/77314373197.pdf
    • https://mcrlclient.com/ckfinder/userfiles/files/demoxem.pdf
    • http://asirius.su/wp-content/plugins/super-forms/uploads/php/files/154b0399aa3efda94ae8afbf8889546c/75799856317.pdf
    • http://chamdure.com/DATA/files/92316594985.pdf
    • http://www.pattyn360.com/upload/forum/files/67465754469.pdf
    • https://microfocus-realize2020mea.com/wp-content/plugins/super-forms/uploads/php/files/0e432370c049b82e6c8e7ae903552729/90417702797.pdf
    • http://veronicanealhome.com/wp-content/plugins/formcraft/file-upload/server/content/files/2/160c393b623a70---8186657960.pdf
    • https://quangcaowebsite.vn/uploads/files/54126145344.pdf
    • http://sjar-tech.com/uploadfile/file///2021062606102571.pdf
    • https://motionslam.com/wp-content/plugins/super-forms/uploads/php/files/bba73aecfedff292b95815a8893ae61c/toliriwinijiziw.pdf
    • https://medbillings.us/lightspeedweb1/file/77304897846.pdf
    • http://fitnessklub-impuls.pl/uploads/assets/file/bibasesogidevaba.pdf
    • http://www.ncstarim.com.tr/wp-content/plugins/super-forms/uploads/php/files/nfimdnuffcd922dgv829lji887/jowebipiwagunipolalazizuw.pdf
    • http://ruilong-ironwork.com/CKEdit/upload/files/78722824880.pdf
    • http://aftckwt.com/uploads/file/62341560068.pdf
    • http://verkoop-je-wagen.be/wp-content/plugins/formcraft/file-upload/server/content/files/160bf47202a859---30919287696.pdf
    • http://tafgambiatours.com/userfiles/file/39476798959.pdf
    • http://bjzjygj.com/fckeditor/editor/filemanager/connectors/php/userfiles/file/75129717947.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/Om9ozkHLxGw/uplcv?utm_term=ensayo+sobre+el+mundo+de+sofia+pelicula+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_off00011073.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x11073 16792 bytes
font_01_sfnt_off0001288a.bin
a1b1a418a7a8a7c050979d06cdaddc66243b35a81e18c9a5bc3e9532d3bd40b5
pdf-font-stream PDF embedded font (sfnt) at offset 0x1288A 11020 bytes
font_02_sfnt_off000141e1.bin
482ac64fb99865e647612069526a9a5ea0b232dccb9f3ee870d50dd7c88555ba
pdf-font-stream PDF embedded font (sfnt) at offset 0x141E1 18596 bytes