Malicious PDF — malware analysis report

Static analysis result for SHA-256 91a75ff2f3cedf0a…

MALICIOUS

PDF

76.4 KB Created: 2021-09-22 13:30:05 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 08ac70aa3681aa8a55ba2786731acfb5 SHA-1: 0009a7865134fa36c9548e53319d58a7e6f49dfb SHA-256: 91a75ff2f3cedf0a5e45b914e862ff2dc4c1f42c8d924b7997a7f6e4a55d616b
164 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs and heuristics indicate it functions as a link farm, directing users to potentially compromised websites that host further malicious PDFs. The presence of a 'download button' heuristic suggests a social engineering lure to trick users into downloading a payload. ClamAV detection and ML classification strongly indicate malicious intent, likely related to phishing or malware distribution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9953

Heuristics 7

  • 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.
  • Visual download / call-to-action button lure low SE_DOWNLOAD_BUTTON
    Document contains a call-to-action phrase ('Click here to download', 'Download Now', etc.) — low-signal unless other findings point to a malicious workflow
  • 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://huntic.ru/uplcv?utm_term=zombie+apocalypse+apk PDF link annotation
    • https://pluviaterra.mx/wp-content/plugins/super-forms/uploads/php/files/f27ccf699e55b73abd2bea06fd11aeb8/velefonubiber.pdfIn PDF document text
    • http://dieukhactransam.com/uploads/files/52261062703.pdfIn PDF document text
    • http://brodart01.com/wp-content/plugins/super-forms/uploads/php/files/hnv3poi4v4siphml00cd1avfvh/gefovitemukofoxonanuruwe.pdfIn PDF document text
    • http://aeskulap24h.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613acc3d5597b---9690431786.pdfIn PDF document text
    • https://hyosungulf.com/uploads/file/vetofuwobelinefowifiwe.pdfIn PDF document text
    • https://ww150001.linebot.net/upfile/files/20210909032507.pdfIn PDF document text
    • http://resheto.ru/users_images/fck/file/jibafinevalegodipigafe.pdfIn PDF document text
    • http://zvezda-rostov.ru/ckfinder/userfiles/files/18533778383.pdfIn PDF document text
    • https://ises.smithpressautomation.com/phpsites/vertical_living/uploads/file/darabike.pdfIn PDF document text
    • https://szabobuszberles.hu/files/files/68907516517.pdfIn PDF document text
    • http://mientrungland.net/uploads/image/files/lufopugijagibilurafeku.pdfIn PDF document text
    • https://www.sudoku-cool.com/ckfinder/userfiles/files/45310297985.pdfIn PDF document text
    • https://get-insurance.in/ckfinder/userfiles/files/98550890839.pdfIn PDF document text
    • http://standardamulet.com/files/files/7835653578.pdfIn PDF document text
    • https://cristalparkhotel.com/ckfinder/userfiles/files/44561161037.pdfIn PDF document text
    • http://tuclubcr.com/campannas/file/ralip.pdfIn PDF document text
    • http://asu78.ru/userfiles/file/54050810642.pdfIn PDF document text
    • http://moriefrusca.com/userfiles/files/8842655428.pdfIn PDF document text
    • http://nsdadventist.org/FCKData/file/69632286562.pdfIn PDF document text
    • https://wsbtitan.com/images/file/67970983715.pdfIn PDF document text
    • http://dogomanhnghia.com/uploads/files/91039246671.pdfIn PDF document text
    • http://hotdeals24x7.com/ci/userfiles/files/75846314979.pdfIn PDF document text
    • https://okud-istra.hr/userfiles/file/5970506620.pdfIn PDF document text
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#In PDF document text
    • http://purl.org/dc/elements/1.1/In PDF document text
    • http://ns.adobe.com/pdf/1.3/In PDF document text
    • http://ns.adobe.com/xap/1.0/In PDF document text
    • http://ns.adobe.com/xap/1.0/mm/In PDF document text
    • http://ns.adobe.com/xap/1.0/rights/In PDF document text
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000c125.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC125 10540 bytes
SHA-256: a33ede963b3d8e018d3be1b96114b2f0459e42750fa785748d5f4e49803b27c0
font_01_sfnt_off0000d901.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD901 19984 bytes
SHA-256: 61d29bd873bc14e2d4bf2bbfa6674458bda47a1de58701d59838ab6d40f0a5ce
font_02_sfnt_off00010c50.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10C50 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1