Malicious PDF — malware analysis report

Static analysis result for SHA-256 ec52592944db28c3…

MALICIOUS

PDF

84.5 KB Created: 2021-08-27 20:29:38 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 5d28f1dbc0a9289badfd9cec226cf66c SHA-1: 39f999ae666f1998b92505037fc818d6040dd8f4 SHA-256: ec52592944db28c3298704a58e06e97e95ccc195b50506ec528286d8648d4196
156 Risk Score

Malware Insights

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

The PDF file was identified as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. The heuristics reveal that the document functions as a link farm, containing numerous external URIs, some of which point to compromised CMS upload storage. This suggests the PDF is designed to lure users to potentially malicious websites, likely for phishing or malware distribution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9991

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://sh-ruiyangcpa.com/userfiles/file/2021-6///2021626116568038.pdf
    • https://www.sabiamente.es/wp-content/plugins/formcraft/file-upload/server/content/files/160ae5f8e039b9---15581733032.pdf
    • http://hgbs.de/userfiles/file/40894110541.pdf
    • https://www.justgym.co.za/wp-content/plugins/super-forms/uploads/php/files/jstgu5lgd2ac1f406iv5r8s0gt/domivebefuruzuresek.pdf
    • http://thefutureofgolf.eu/wp-content/plugins/formcraft/file-upload/server/content/files/160b3ca8a60dd9---golofapozosimefalesojivu.pdf
    • http://dailitara.lt/bites/uploads/file/78438445029.pdf
    • http://bycongroup.com/UserFiles/file/lukesibenakotil.pdf
    • http://cuatudongbinhduong.net/uploads/files/85609184426.pdf
    • https://www.coconutlodge.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609be87e21df4---fetawaxe.pdf
    • http://fresh-j.info/images/uploadedimages/file/rixikunexuka.pdf
    • http://www.louthadventures.ie/wp-content/plugins/formcraft/file-upload/server/content/files/16094d6ec4a6e3---mivodojebe.pdf
    • http://samafb.org/uploadfilefiles/lutakiruvotirojasajixopu.pdf
    • https://xigmatek.com/upload/files/3600136592.pdf
    • https://massagetheory.ca/wp-content/plugins/super-forms/uploads/php/files/faefe290ed2c62ea35b0d8b8dcb7dad1/47646654716.pdf
    • https://noukos.gr/wp-content/plugins/formcraft/file-upload/server/content/files/160a076f0224b0---89135827304.pdf
    • https://popa.com.br/wp-content/plugins/super-forms/uploads/php/files/83d8f2d474747746fb37853cfa5bfe4e/3190244934.pdf
    • http://industrialdevices.in/uploads/timave.pdf
    • http://kiko168.com/UploadFile/file/20210816092552832.pdf
    • http://twxcd.com/img-aim/files/ravujebos.pdf
    • https://clubelsendero.com/img_pag/file/41378852684.pdf
    • https://www.kiteschule-kiel.de/wp-content/plugins/formcraft/file-upload/server/content/files/160836fc25a00a---diveka.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/3vuEKuznOb8/uplcv?utm_term=the+trial+of+the+sea+lion+wow+classic
    • http://zs.tom.ru/jsplugins/ckfinder/userfiles/files/kapeluxubuzuzezokifepegir.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 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000c8fb.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xC8FB 16792 bytes
font_01_sfnt_off0000e10c.bin
e896d0c9c6509c93731645541c0836c845742b74f7fde2e8ff5e94baacc6a6a0
pdf-font-stream PDF embedded font (sfnt) at offset 0xE10C 16632 bytes
font_02_sfnt_off0000f899.bin
bc29b0c37104589eff742ff396e400974ba2c8ccaf3bc4dc05885ac83169fe3d
pdf-font-stream PDF embedded font (sfnt) at offset 0xF899 19360 bytes
font_03_sfnt_off00012ae7.bin
de266a6346b65456b4ee1697b0e22a5a51b0f5c41b6356fde75efb730b48e8f0
pdf-font-stream PDF embedded font (sfnt) at offset 0x12AE7 10484 bytes