Malicious PDF — malware analysis report

Static analysis result for SHA-256 661b8c21ea583eda…

MALICIOUS

PDF

85.9 KB Created: 2021-08-15 18:44:32 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-04
MD5: 686a63dc09e29ea8252954af412f7f1e SHA-1: 543466681fae06f93a1a93af8d5cab307aa11b42 SHA-256: 661b8c21ea583eda808dbac437a3fd458c2396538930b84b4b059c0d855fdc95
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 0.9982

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 http://lbs.ac.at/wp-content/plugins/super-forms/uploads/php/files/chlmte9sf741mu4ocd7o34g2s3/2176870161.pdf In PDF document text
    • http://sweatrinserepeat.com/ckfinder/userfiles/files/53450795142.pdfIn PDF document text
    • http://b-solutions.net/userfiles/file/63463221094.pdfIn PDF document text
    • http://www.cargeacrew.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160c3e54e890dd---57774641668.pdfIn PDF document text
    • http://soflacops.com/clients/83266/File/falemexesibesatapiwa.pdfIn PDF document text
    • https://upbfassadenbau.com/upload/file/wisegopoxitonuv.pdfIn PDF document text
    • https://alshamiltrading.com/alshamilfiles/file/72140892343.pdfIn PDF document text
    • http://cloverpark1961.com/clients/6/6a/6a73a08bb68f643008adb5efbbb44e43/File/13902725897.pdfIn PDF document text
    • http://xn--90ad5ackt1d.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/ab1956075c8c3f971c3bb7f030e1f0a4/buteluginovudi.pdfIn PDF document text
    • http://laarakkers.com/ckfinder/userfiles/files/40901814649.pdfIn PDF document text
    • https://championsforchildren.org/wp-content/plugins/super-forms/uploads/php/files/002724979886020eca5b2c72720b9a1d/59908288215.pdfIn PDF document text
    • http://dailyxedayhang.com/userfiles/files/61985255500.pdfIn PDF document text
    • http://ausafe.net/images/art/files/ruvexiwizafikuvowubur.pdfIn PDF document text
    • http://veronicanealhome.com/wp-content/plugins/formcraft/file-upload/server/content/files/2/1607da6fca6c10---74997604377.pdfIn PDF document text
    • http://amfmeg.org/wp-content/plugins/formcraft/file-upload/server/content/files/160badf4c70f5c---87410562106.pdfIn PDF document text
    • http://wallsfamilyreunion.com/clients/876683/File/22100225740.pdfIn PDF document text
    • http://szwygs.com/upload/62792622282.pdfIn PDF document text
    • http://konberdbio.com/upload/files/zosozunawuvi.pdfIn PDF document text
    • http://clair-environnement.eu/catalogue_dynamique/file/6885318746.pdfIn PDF document text
    • https://reformedgeneration.com/userfiles/file/71153632994.pdfIn PDF document text
    • http://kaufdeinauto.de/wp-content/plugins/formcraft/file-upload/server/content/files/1609644963620a---76629026659.pdfIn PDF document text
    • https://www.conkite.com/wp-content/plugins/super-forms/uploads/php/files/78ab1434d70e3a1023754cf3a71e9765/51094820080.pdfIn PDF document text
    • https://monarchwinemerchants.com/wp-content/plugins/super-forms/uploads/php/files/f4271992f44d4290281c19c4a28cdeb6/7449759017.pdfIn PDF document text
    • http://www.oknookna.pl/wp-content/plugins/formcraft/file-upload/server/content/files/160e1803ed795b---zuxufex.pdfIn PDF document text
    • https://stellabakingcompany.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606cca8267b0e---xuxupuwabupusanipixe.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/3CAf4wW3hvY/uplcv?utm_term=chashme+baddoor+full+movie+free+download+mp4moviezPDF 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 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000eb30.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEB30 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00010342.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10342 16872 bytes
SHA-256: 4c7a826d3b08255f41be1822a80625ba8ffd7e63377a996e629a960cf3c801c6
font_02_sfnt_off00012edb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12EDB 11228 bytes
SHA-256: 7e6e9de1a07382af34f27a691ced24b60dd7288b709feaf7fe0b2c822dcfd63e