Malicious PDF — malware analysis report

Static analysis result for SHA-256 55d11da7e6e16ed0…

MALICIOUS

PDF

77.6 KB Created: 2021-09-03 19:54:52 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-23
MD5: f21f588d04ddcb0a8435f16b240ed822 SHA-1: 0cb440cea78c5ccbdef0a084fd88fbb908c6a407 SHA-256: 55d11da7e6e16ed07d8934633d88a0241eea4e1ee6a95c5dfaf839605055ea8d
196 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

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

Machine Learning

  • Nyx PDF Classifier malicious score 0.9976

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
  • Password-protected archive handoff high SE_PASSWORD_ARCHIVE_LURE
    Document gives password instructions for an archive or attachment — often used to keep payloads encrypted until after gateway scanning
  • 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://glass-haus.ru/wp-content/plugins/super-forms/uploads/php/files/e93e33394057f242ebbd036c031a59b3/67712663373.pdf In PDF document text
    • https://thepetrichortouch.com/wp-content/plugins/super-forms/uploads/php/files/ni58h9233q0ng1td7jjs6uctvr/wurapefolijagoloxapaguw.pdfIn PDF document text
    • https://nocnepal.org.np/ckfinder/userfiles/files/naxevotopi.pdfIn PDF document text
    • https://cavalier-hundezucht.ch/userfiles/file/74956899141.pdfIn PDF document text
    • http://polyalpan.hu/_user/file/tiparowawuvexed.pdfIn PDF document text
    • http://chamdure.com/DATA/files/60169398806.pdfIn PDF document text
    • http://sosnovgeo.ru/userfiles/file/57759809471.pdfIn PDF document text
    • https://blueridgelightingandcontrols.com/wp-content/plugins/super-forms/uploads/php/files/6b9bc6d32c18bfaae232c3250837910e/85911887687.pdfIn PDF document text
    • https://www.vibrationmonitoring.asia/wp-content/plugins/formcraft/file-upload/server/content/files/160c76acea4b38---wapewigugenepazoxalu.pdfIn PDF document text
    • https://energooptima.hu/upload/File/10505422506.pdfIn PDF document text
    • https://gogreenonline.net/userfiles/image/fckeditor/file/81359305727.pdfIn PDF document text
    • http://uk-finansist.ru/userfiles/file/bizubivoveve.pdfIn PDF document text
    • https://tocgia247.com/wp-content/plugins/super-forms/uploads/php/files/k4dnfbn9anbe5a3c3v92luh6hq/nisozipawogisefobi.pdfIn PDF document text
    • https://bywuf.org/upload/editor/files/77043667810.pdfIn PDF document text
    • http://pck.malopolska.pl/wp-content/plugins/super-forms/uploads/php/files/e8c72acb550539f1e4451ae9dce60aee/58549652502.pdfIn PDF document text
    • http://skuplaptop.pl/wp-content/plugins/formcraft/file-upload/server/content/files/160a9511992e4d---247779857.pdfIn PDF document text
    • http://for-rent-aalst.com/wp-content/plugins/formcraft/file-upload/server/content/files/160768c69e195d---dozubixiwikurizewumoserem.pdfIn PDF document text
    • http://xn--j1aii.su/userfiles/file/rolowadekubimiresu.pdfIn PDF document text
    • http://aaexpansionjoint.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606d91ef095a3---44928962.pdfIn PDF document text
    • http://hzdsbg.com/uploadfile/1630642580.pdfIn PDF document text
    • http://xn--9w3b11kh5l.com/ckupload/files/vofak.pdfIn PDF document text
    • http://www.sunargrup.com.tr/wp-content/plugins/super-forms/uploads/php/files/qpuh0bhevdt0gri80el45013p2/posetikanujakipimi.pdfIn PDF document text
    • https://zoldlepes.hu/userfiles/file/1005732183.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/S30rS-6n6vg/uplcv?utm_term=sap+pm+preventive+maintenance+pdfPDF 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_off0000c903.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC903 18276 bytes
SHA-256: 89b57e2304a48b2267f8bfa55dbb92ee1b5a624f52dd2bfcf98c560f81e82abf
font_01_sfnt_off0000f86c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF86C 10588 bytes
SHA-256: 0619daca585b0b3d272404c4147c63de082460ac2a1d68c3b8c2077387e4b219
font_02_sfnt_off00011098.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11098 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1