Malicious PDF — malware analysis report

Static analysis result for SHA-256 839ebc1503cbc25e…

MALICIOUS

PDF

165.2 KB Created: 2021-06-27 01:26:44 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-15
MD5: b52041f29a6c85f62f0539d3e14c4803 SHA-1: ac7ce9d3a1934e0f39d25f1dd17308169362a8d3 SHA-256: 839ebc1503cbc25e4ea47c35f9f88a6f9a85ffaf674a94df1fb1d8d2cca96046
156 Risk Score

Malware Insights

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

The PDF contains a link farm pointing to numerous compromised WordPress sites and other disposable hosting. The ClamAV detection and ML classifier strongly indicate malicious intent, likely to lure users to malicious content or phishing sites. No scripts were extracted, but the structure and URL patterns are consistent with a phishing or malware distribution lure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9727

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 http://hungbuloon.com/media/ftp/file/57455725094.pdf In PDF document text
    • https://gtsonline.nl/wp-content/plugins/super-forms/uploads/php/files/lfkc31ng510hjl83ut377vgs6r/nebuzanojeregutegel.pdfIn PDF document text
    • http://bergfin.se/wp-content/plugins/formcraft/file-upload/server/content/files/16098533d9bf0c---8504257347.pdfIn PDF document text
    • http://forglass.sk/userfiles/file/58115599618.pdfIn PDF document text
    • https://acronimocostanzo.com/userfiles/file/kojepas.pdfIn PDF document text
    • http://mesotects.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ca007d2387f---93996284737.pdfIn PDF document text
    • http://nfraccon.org/userfiles/file/97037069050.pdfIn PDF document text
    • https://www.davidcosz.de/wp-content/plugins/super-forms/uploads/php/files/v6jkrl3rpjutmmi1es7coprmpt/lenudituvixoweko.pdfIn PDF document text
    • https://jdbailbonds.com/wp-content/plugins/super-forms/uploads/php/files/5d88e8f08f65531b8e24832d2eaa5f8f/58109861505.pdfIn PDF document text
    • https://coimbatorepressclub.com/FCKeditor/userfiles/file/91698717616.pdfIn PDF document text
    • https://infravoip.com/wp-content/plugins/super-forms/uploads/php/files/63cdfff4df7eafd265d1ef99914220a6/25296689148.pdfIn PDF document text
    • http://aliancegroup.su/wp-content/plugins/formcraft/file-upload/server/content/files/160b0ae9147dd9---94337503894.pdfIn PDF document text
    • https://earthchartercities.org/wp-content/plugins/formcraft/file-upload/server/content/files/16084941c01310---71631488398.pdfIn PDF document text
    • https://bursac.net/userfiles/file/segivatuw.pdfIn PDF document text
    • http://gesundezellen.de/neu/userfiles/file/zavipuzu.pdfIn PDF document text
    • http://jinanxintiandi.com/userfiles/files/7619340541.pdfIn PDF document text
    • https://www.lumisolar.pe/wp-content/plugins/formcraft/file-upload/server/content/files/160a347ee915a2---13052293342.pdfIn PDF document text
    • https://medtek.vn/storage/file/xodod.pdfIn PDF document text
    • http://bukharasuwanee.com/sites/default/files/file/43768487421.pdfIn PDF document text
    • https://avantkart.com/wp-content/plugins/super-forms/uploads/php/files/cbkh9hmuiif91pjsds1bqe312i/pokopaf.pdfIn PDF document text
    • https://cls-toronto.com/wp-content/plugins/super-forms/uploads/php/files/be6f05090855b5136cc69ba1f91b5bd3/9295121191.pdfIn PDF document text
    • http://shannonlakeestates.org/fck_images/file/gafegituv.pdfIn PDF document text
    • http://slenderclub.cz/ckfinder/userfiles/files/15056104301.pdfIn PDF document text
    • https://lecormier-menuiserie.com/www/upload/files/1968202178.pdfIn PDF document text
    • http://www.urbanwaterways.info/files/55567790882.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/GLLx1DTH0VQ/uplcv?utm_term=fear+and+wisdom+in+the+biblePDF link annotation
    • 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 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0001f22f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1F22F 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00020a40.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x20A40 19524 bytes
SHA-256: 615cd01330a9e1665363e95865f44159ce7c5acb7d41e3ffa6207d843c8aa9de
font_02_sfnt_off00022bce.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x22BCE 10716 bytes
SHA-256: e576447718d28e0e0df2256045c36cd59ce5e76842395faad041c23c8b8136ae
font_03_sfnt_off00024432.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x24432 29472 bytes
SHA-256: 62400230f39c59e66d34c8438177509b03729b10d9c8e6e92c3bb9ae0e8fcd3e