Malicious PDF — malware analysis report

Static analysis result for SHA-256 ec4cd848aa616a0e…

MALICIOUS

PDF

81.2 KB Created: 2021-07-02 00:36:28 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: ecb83865ad07c0836f9cf2ceb747f0a4 SHA-1: 1dfbcb42e0e4fb03658e0cbe07accb585ca9a788 SHA-256: ec4cd848aa616a0e97ca6f1329005b94bb469fbc692992792779e7ce3526a161
156 Risk Score

Malware Insights

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

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. Heuristics reveal it functions as a link farm, directing users to compromised WordPress upload storage and other disposable hosting sites. The presence of numerous unknown URLs suggests a phishing or malware distribution campaign.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9949

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://www.rogierstoel.nl/wp-content/plugins/super-forms/uploads/php/files/je9tva502mfq6k3ie4vaigtk0e/fokewududonaf.pdf
    • https://www.analfissur.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608475a0e8dce---lifunomejajol.pdf
    • http://amako-ra.com/wp-content/plugins/super-forms/uploads/php/files/c72fe0b61f06e6ed9ae8725fc4391df3/64467672717.pdf
    • https://www.horisunmauritius.com/wp-content/plugins/super-forms/uploads/php/files/91267669c0ba533e8dfa80a5818af288/goruberefimikulof.pdf
    • https://ienter.bg/files/91728944780.pdf
    • https://www.jemelectric.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608765273e91e---91091405823.pdf
    • http://asja-doll.ru/userfiles/file/damidemepumopogifa.pdf
    • https://www.saltriot.com/wp-content/plugins/super-forms/uploads/php/files/62edeb779ee643fa74a82a833ef7ecef/zeritavon.pdf
    • http://stjconsulting.it/userfiles/files/7168561776.pdf
    • http://xn--90ad5ackt1d.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/4cf13d9e5bef87ca80b7f6c1c0c8aeb5/nimitudojun.pdf
    • http://www.majoriscambio.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160a8031987876---35713811013.pdf
    • http://kirks-pool.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606ee5487dbce---93231697065.pdf
    • https://studiogreenwich.ru/wp-content/plugins/super-forms/uploads/php/files/bcd3a4ba9ba7be0a7a415d228485eb0d/vekalogudasujukoged.pdf
    • http://glina-master.ru/admin/ckfinder/userfiles/files/bekejiwojejosabu.pdf
    • http://piqiso.ru/userfiles/file/woxafugivimusezi.pdf
    • https://avenirpourtous.fr/wp-content/plugins/formcraft/file-upload/server/content/files/1606cc8d42dd08---868932057.pdf
    • http://atlantichomeportugal.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a56a03ceafd---18447799353.pdf
    • http://yousefmaktabi.com/ckfinder/userfiles/files/21133847021.pdf
    • http://bezagsecurity.cz/userfiles/60365321334.pdf
    • http://altelaw.com/uploads/image/file/55478626149.pdf
    • https://bykevin.com/wp-content/plugins/super-forms/uploads/php/files/9416c10e1bb1ac7743564ac14697823f/ponisarujomisipiduzakawug.pdf
    • https://floorco.allianceflooring.net/wp-content/plugins/super-forms/uploads/php/files/a91f2ac8fc47bf50e1875567c87a2f7b/bikejagekurufesotewap.pdf
    • http://eksan-ltd.com/userfiles/file/redaf.pdf
    • http://www.contectrade.hu/fckfiles/file/59244507109.pdf
    • http://galluccifaibano.com/userfiles/file/36846015845.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/BkSY9tpko7c/uplcv?utm_term=use+of+nahco3
    • 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_off0000d7da.bin
9aef3d61f5c4f391765687cd5fcbdca3e75b9f92e2f1e5900b681d29ad2cb41d
pdf-font-stream PDF embedded font (sfnt) at offset 0xD7DA 10276 bytes
font_01_sfnt_off0000eefd.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xEEFD 16792 bytes
font_02_sfnt_off0001070f.bin
667cd1e50b1c70e863b40290095d9c7e2b43117f81f746944d7c3c8e036a3860
pdf-font-stream PDF embedded font (sfnt) at offset 0x1070F 18336 bytes