Malicious PDF — malware analysis report

Static analysis result for SHA-256 83fa8469083f6c26…

MALICIOUS

PDF

78.5 KB Created: 2021-09-03 18:52:42 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: f0903a2dc3c414aaedc0c006885ec71b SHA-1: 641a1e23a22d56c3ad5b754677bc41516b72dcc0 SHA-256: 83fa8469083f6c26e12f8adb0b65b831ca39bd90bc7257defc9b61794ebc5bed
164 Risk Score

Malware Insights

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

This PDF document was flagged as malicious by ClamAV and an ML classifier. The file embeds a large number of external links characteristic of an SEO link farm, many hosted on compromised CMS upload directories and presents a deceptive download button. Specific URLs and indicators for this sample are listed in the indicators section.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9978

Heuristics 7

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://allytemp.ru/uplcv?utm_term=worksheet+english+for+kg2 PDF link annotation
    • https://middletonchambers.com/ckfinder/userfiles/files/kezirororuxonogat.pdfIn PDF document text
    • http://www.idenet.net/wp-content/plugins/formcraft/file-upload/server/content/files/1607ffc01de782---70797519792.pdfIn PDF document text
    • https://areshin.ru/wp-content/plugins/super-forms/uploads/php/files/481024412f36f20a601baee459447a24/33689660922.pdfIn PDF document text
    • https://relleno-acidohialuronico.com/wp-content/plugins/super-forms/uploads/php/files/66503308f69a9533498bbff952e37bcf/9425627576.pdfIn PDF document text
    • https://aradovan.com/userfiles/file/42544136719.pdfIn PDF document text
    • http://www.investing-in-women.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609d653870b6b---42529492642.pdfIn PDF document text
    • https://aydin-elektrik.com/resimler/files/26196124441.pdfIn PDF document text
    • http://www.pianoszimmermann.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160bc9c0d5694e---23522167721.pdfIn PDF document text
    • http://jyjwqj.com/uploadfile/file///2021062719491340.pdfIn PDF document text
    • https://popcouncilinstitute.org/wp-content/plugins/super-forms/uploads/php/files/e512441f88b07f78af605c32ca8bf111/14351920129.pdfIn PDF document text
    • http://kiddeefire.com/media/userfiles/files/75201958173.pdfIn PDF document text
    • https://member-amz-seller-system.de/wp-content/plugins/super-forms/uploads/php/files/305eca6ae18857debe41708c422d3542/78875080093.pdfIn PDF document text
    • http://purofirstli.com/userfiles/files/jopotilesinim.pdfIn PDF document text
    • http://csc010.com/userfiles/file/20210616230409_6xhtps.pdfIn PDF document text
    • http://zopos.zohukum.com/ckfinder/userfiles/files/majitepudipemofo.pdfIn PDF document text
    • https://nomortiga.com/contents/files/94342985836.pdfIn PDF document text
    • http://erfolgsapp.de/wp-content/plugins/formcraft/file-upload/server/content/files/160c389cd307ec---faxonupetepared.pdfIn PDF document text
    • http://icoenergia.com/userfiles/files/dezaniloxa.pdfIn PDF document text
    • https://member-amz-seller-system.de/wp-content/plugins/super-forms/uploads/php/files/44da770c2bfb8f18b578625026613f6e/15102424078.pdfIn PDF document text
    • http://signexpowholesale.com/project-new/christianbook/upload_images/file/furizagadagitexu.pdfIn PDF document text
    • http://saopauloairporttransfers.com/ckfinder/userfiles/files/54558277243.pdfIn PDF document text
    • https://halobysciton.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c778f3727f6---notufikugevulajonesiwuwi.pdfIn PDF document text
    • https://akarchlight.com/wp-content/plugins/super-forms/uploads/php/files/de5e6d3cbe16892f985bd8f25d5f5b32/49668035971.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_off0000cf53.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCF53 10536 bytes
SHA-256: 29d485bfc1938b5fa759534e3913cdea98fa592778c368f4e0f98987666531b3
font_01_sfnt_off0000e756.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE756 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000ff68.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFF68 17208 bytes
SHA-256: d5220f7b7bf062cae70405b7376a5a670187d9dd169398c1609dbdc37d0d06d0

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