Malicious PDF — malware analysis report

Static analysis result for SHA-256 82098680c44cc4c4…

MALICIOUS

PDF

80.4 KB Created: 2021-09-13 01:47:05 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: c1fa422a4e87a94b238d2d84b4e00178 SHA-1: 7985e0ab9b992c47785b5df7b64b8ec930c9047e SHA-256: 82098680c44cc4c4ab691f6c16ac51b03dd0033570524f132cb94082e791312f
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF document identified by ClamAV as a phishing trojan. It contains numerous URLs, many of which point to compromised CMS uploads or disposable hosting, suggesting a link farm designed to redirect users. The ML classifier also strongly indicated maliciousness. The primary function appears to be directing users to external, potentially malicious, websites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9981

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://garglob.ru/uplcv?utm_term=vatsyayana+book+pdf+malayalam PDF link annotation
    • http://nbc.ua/design/pic/file/88505973756.pdfIn PDF document text
    • http://chagatea.ru/wp-content/plugins/super-forms/uploads/php/files/3c697e59ccb6fe0dc60ec51066c9a9a8/23088779576.pdfIn PDF document text
    • http://xn--80aadq3ae7aa5k.xn--p1ai/upload/file/67543476213.pdfIn PDF document text
    • https://www.tctnanotech.com/wp-content/plugins/super-forms/uploads/php/files/e090ac35b72eb05fa82adaea9c9f9e1f/tanoniwej.pdfIn PDF document text
    • http://grupposcorcia.it/userfiles/files/47076327912.pdfIn PDF document text
    • https://mariapolis.es/ckfinder/userfiles/files/96557888526.pdfIn PDF document text
    • http://sevinctekstil.com/resimler/files/gogawejamekoka.pdfIn PDF document text
    • http://blueyee.com/upload/file/100013044227.pdfIn PDF document text
    • http://gelinyuanyi.com/upload_fck/file/2021-9-8/20210908193605467431.pdfIn PDF document text
    • http://aaronandanthony.com/userfiles/files/tegizibajapefanomimijobik.pdfIn PDF document text
    • https://tenutaedone.com/filesUploads/file/bolizetejo.pdfIn PDF document text
    • http://tiszaladany.hu/upload/file/16578097697.pdfIn PDF document text
    • https://christianklein.eu/Quansis/ckfinder/userfiles/files/95113138604.pdfIn PDF document text
    • http://lookupagency.es/wp-content/plugins/formcraft/file-upload/server/content/files/161374becd4b54---tunemizun.pdfIn PDF document text
    • https://store-connector.com/_upload_bilder/_filemanager/file/lojupuredoralofup.pdfIn PDF document text
    • https://taiwan-tiaya.com/upload/tiaya_official/files/lilikivodadonexowa.pdfIn PDF document text
    • https://llibreriaha.com/img/events/file/75203274999.pdfIn PDF document text
    • http://gnox.vn/upload/files/7503511435.pdfIn PDF document text
    • http://www.tiande-global.com/ckfinder/userfiles/files/3928921516.pdfIn PDF document text
    • http://slkuang.com/v15/Upload/file/20219954762743.pdfIn PDF document text
    • https://agsposure.org/wp-content/plugins/super-forms/uploads/php/files/e99b99d19f2bbe19ed82907c326701a3/2241920255.pdfIn PDF document text
    • http://intertexmedical.com/userfiles/files/riginumiroletefafibadad.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_off0000cb21.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCB21 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000e333.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE333 21516 bytes
SHA-256: cacc58d3f22dfb3ab4bce3a706b19a69e82f7886d34963bd62004d5b33a9efa6
font_02_sfnt_off00011bbd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11BBD 10652 bytes
SHA-256: 3f025a41a27d71cc60919b3e3d0f2b9caebabde20374d31c03fe43208da37697