Malicious PDF — malware analysis report

Static analysis result for SHA-256 d5a1d5a015aa3410…

MALICIOUS

PDF

105.4 KB Created: 2021-07-22 16:09:44 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 22c429ca3d3359a7eaf9e3fe65f669fa SHA-1: fc818c44c548176d678f5fc859c5c94f53f981f8 SHA-256: d5a1d5a015aa3410dae516b9ad96aa845099f318bcc9320e58ee681159bb431a
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 pointing to files hosted on compromised CMS uploads or disposable hosting. The ML classifier strongly indicates maliciousness. While no scripts were extracted, the structure suggests a link farm designed to lead users to potentially malicious content hosted elsewhere.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9861

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://universal4shipping.net/userfiles/file/70699639087.pdf
    • https://www.criteriainvest.com.br/wp-content/plugins/super-forms/uploads/php/files/57fbiockfnvhco6b4f96i5htga/zaxumabevatevudivag.pdf
    • https://mission4recruitment.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b31b631cc71---55576528850.pdf
    • https://dienlanhhonganh.com/images/pic/file/26508548329.pdf
    • http://eia-edu.com/userfiles/file/wodinejozugigekafaxati.pdf
    • http://exactblue.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608a46382ac1e---tuvuzuruvinobimomixikuz.pdf
    • http://artospace.com/pics/file/76355399644.pdf
    • https://zevkotodoseme.com/upload/ckfinder/files/dubuvotasu.pdf
    • http://bioterapiazabiegi.pl/obrazy/file/82860554610.pdf
    • http://kaufdeinauto.de/wp-content/plugins/formcraft/file-upload/server/content/files/160983922db56c---sopopilu.pdf
    • https://trucraftsmanship.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c03ccd1bfca---kaxagutamapamolilekasovel.pdf
    • https://frontiersneurophotonics.org/wp-content/plugins/formcraft/file-upload/server/content/files/1/160b4d77f362a8---26091712770.pdf
    • https://krimgranit.ru/wp-content/plugins/super-forms/uploads/php/files/c348eda20c901709df53a5b34361d318/75578081158.pdf
    • http://hosungtour.net/FileData/ckfinder/files/20210718_3C806455FEB94286.pdf
    • https://proff-doors.ru/wp-content/plugins/super-forms/uploads/php/files/19f2c44c5808b8d2e7b0ae0ba2aa34ed/23624344157.pdf
    • http://pericosrentcar.com.mx/wp-content/plugins/formcraft/file-upload/server/content/files/1608c62f085122---xezuwirem.pdf
    • https://www.varishastalari.com/wp-content/plugins/formcraft/file-upload/server/content/files/16072fb1da5c09---gigokozorazekugidutobe.pdf
    • http://ardechetendancebrut.fr/userfiles/ardechetendancebrut.fr/file/ramipeketezimojepajan.pdf
    • http://automsystem.com/UploadFile/file/20210503041851722.pdf
    • http://niengrangchuyensau.com/upload/contentFile/file/72499376213.pdf
    • https://www.msolartop.cz/wp-content/plugins/formcraft/file-upload/server/content/files/160c3764a85251---12928651970.pdf
    • http://www.fashiongale.ro/userfiles/files/kedefikox.pdf
    • http://agapetown.net/ckfinder/userfiles/files/pinimikabewi.pdf
    • http://alpha-th.com/userfiles/file/dafawufewavozepa.pdf
    • https://kvgrup.com.ua/wp-content/plugins/formcraft/file-upload/server/content/files/160857729a381c---5348451357.pdf
    • https://transit-connection.com/userfiles/files/95438356588.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/PmAiG5ZyT-k/uplcv?utm_term=smarter+than+you+think+clive+thompson+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_off0001374c.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x1374C 16792 bytes
font_01_sfnt_off00014f63.bin
fbfcd58f5a86d5f0a8b8a6e9574b15d01400ef813063713abc619cc0ed79abbd
pdf-font-stream PDF embedded font (sfnt) at offset 0x14F63 11332 bytes
font_02_sfnt_off000169d9.bin
3fcd303eefd8652bddf617586cc9564ffd0d00a99b66ed04bf82f76093bb759c
pdf-font-stream PDF embedded font (sfnt) at offset 0x169D9 17112 bytes