Malicious PDF — malware analysis report

Static analysis result for SHA-256 a91302e79e6e640b…

MALICIOUS

PDF

83.2 KB Created: 2021-09-11 04:48:22 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 6ef3ebffe0d163b421de1438ac260ab4 SHA-1: de33b15b6deba2be80ba20c2d11c3b095ce007f3 SHA-256: a91302e79e6e640b723b538b34a7f1fb37333383bb85e0e94e6cece016fd9c2a
156 Risk Score

Malware Insights

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

The file is identified as malicious by ML classifiers and ClamAV, with multiple heuristics indicating it functions as a link farm. The URLs point to compromised CMS uploads and disposable hosting, suggesting an attempt to lure users to malicious sites. The PDF structure and embedded URIs are consistent with phishing or malware distribution tactics.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9956

Heuristics 6

  • 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.
  • 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://crysiq.ru/uplcv?utm_term=mv+bit+master+apk+download PDF link annotation
    • https://provisionsinternational.com/wp-content/plugins/formcraft/file-upload/server/content/files/16138f6ea441a5---40763256328.pdfIn PDF document text
    • http://oldmotorsclub.com/files/file/33710311375.pdfIn PDF document text
    • http://logicamail.it/draft/media/xomala.pdfIn PDF document text
    • https://balbok.net/admin/ckfinder/userfiles/files/debovixaritinir.pdfIn PDF document text
    • https://protraderin.com/userfiles/file/nenupojizabelepume.pdfIn PDF document text
    • http://tensoinox.com/userfiles/files/25549846189.pdfIn PDF document text
    • http://hellnocancershow.com/wp-content/plugins/formcraft/file-upload/server/content/files/161334118c29b2---75186546458.pdfIn PDF document text
    • http://kayapalinakliyat.net/file/84445047338.pdfIn PDF document text
    • http://briztravel.com/upload/files/vibowexolibekuru.pdfIn PDF document text
    • http://webinaris.training/ckfinder/userfiles/publics/files/62726710196.pdfIn PDF document text
    • http://sorokolaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/labobi.pdfIn PDF document text
    • https://aprilboya.com/userfiles/file/79684196611.pdfIn PDF document text
    • https://plumcourse.com/wp-content/plugins/super-forms/uploads/php/files/505ddba299125253a6887ec65df10e0e/74299540797.pdfIn PDF document text
    • http://openendrep.com/userfiles/files/zigasilukubijus.pdfIn PDF document text
    • http://zhuoxinlaw.com/userfiles/file/20210906085601_1520924550.pdfIn PDF document text
    • http://willettelaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/baxufuvamaxu.pdfIn PDF document text
    • http://metallpress.info/files/xixusidogivugojawefamimo.pdfIn PDF document text
    • https://organicfertilizerproduction.com/d/files/vewowazesitiregos.pdfIn PDF document text
    • http://topp.pl/_topp/file/1917137184.pdfIn PDF document text
    • https://kamber.dk/wp-content/plugins/super-forms/uploads/php/files/7005dfa70ee8066dcd1a914e52ccd4ec/zubepobajulolij.pdfIn PDF document text
    • https://eltechma.com/zdjecia/fck/file/65102081623.pdfIn PDF document text
    • https://wolfgang-photography.com/userfiles/files/34049781479.pdfIn PDF document text
    • https://valve-toho.com/userfiles/file/53477004697.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_off0000db9a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDB9A 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f3b1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF3B1 10928 bytes
SHA-256: 7c87ee826a0bf9bf71063d8ddd370ebe14edc37a2fb404f0ba65550675791ad0
font_02_sfnt_off00010cdc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10CDC 19404 bytes
SHA-256: edeac59142c0a54a9d3610e5fcc11b4e52b0f80607c8ef822fb9967e747b5a29