Malicious PDF — malware analysis report

Static analysis result for SHA-256 82b21005b9bd28fc…

MALICIOUS

PDF

78.6 KB Created: 2021-09-23 02:03:37 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 779a85ad987e3366c51240effdc41fc9 SHA-1: 97ac1750a0661a39318294f544159a2cd45a0d85 SHA-256: 82b21005b9bd28fc138a86c7c1b00f781d3b0eec97295fd246a29d7d5bb45624
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF contains a link farm pointing to numerous disposable domains and compromised CMS upload storage, a common tactic for phishing or distributing further malware. The ML classifier and ClamAV detection strongly indicate malicious intent, specifically identified as a phishing trojan. The document body is heavily obfuscated and appears to be generated by wkhtmltopdf, lacking readable content to infer a specific lure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9978

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://infrive.ru/uplcv?utm_term=harry+potter+online+streaming+movies PDF link annotation
    • https://chetanaus.org/bheru/uploadfiles/file/gizugivawepunaruwipus.pdfIn PDF document text
    • http://cartopack.com/Images/file/nudunimebanuvopiful.pdfIn PDF document text
    • http://theydeserveastamp.org/wp-content/plugins/formcraft/file-upload/server/content/files/1613c890f8371f---jodekumowum.pdfIn PDF document text
    • http://zhuoxinlaw.com/userfiles/file/20210923063441_1125974094.pdfIn PDF document text
    • http://electriccityusa.com/images/fck_uploads/file/lerexe.pdfIn PDF document text
    • http://boatmonies.com/uploads/files/bedizasosa.pdfIn PDF document text
    • http://amtusa.com/wp-content/plugins/formcraft/file-upload/server/content/files/16132dbe100c3e---nejuvu.pdfIn PDF document text
    • https://learnrkb.jugalbandiresearch.com/ckfinder/userfiles/files/47547646950.pdfIn PDF document text
    • https://garnizone.com/userfiles/file/40238553207.pdfIn PDF document text
    • http://zzquansu.cn/d/files/65391930491.pdfIn PDF document text
    • http://jpiano.net/userData/ebizro_board/file/7539300801.pdfIn PDF document text
    • https://kantankacreative.com/wp-content/plugins/super-forms/uploads/php/files/a31fd2f772b4d46a023cfef00d60d189/rapujuterumop.pdfIn PDF document text
    • https://insolite.lu/img/userfiles/files/65938070268.pdfIn PDF document text
    • https://ksdc.in/userfiles/file/83713282441.pdfIn PDF document text
    • http://ticketsperiodico.com/galeria/files/wulakozoxor.pdfIn PDF document text
    • http://cjmfgx.morefriendship.com/upload/files/98201980003.pdfIn PDF document text
    • http://omni-links-europe.com/images/blog/file/98087755555.pdfIn PDF document text
    • https://centrorevisionimonregalese.it/file/nenabukemomelorilodis.pdfIn PDF document text
    • http://saothienemb.com/uploads/images/files/79742427338.pdfIn PDF document text
    • http://101-games.ru/images/uploads/files/gaderafebutusage.pdfIn PDF document text
    • http://inter-travel.hu/_user/file/fufodanuwumi.pdfIn PDF document text
    • https://mimpishio1bet.com/contents/files/pulogimekikovigaganalawe.pdfIn PDF document text
    • http://gldbirdgel.com/user_img/files/32599804139.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_off0000cd66.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCD66 10764 bytes
SHA-256: 8993251c140add3110c02134ddfe373cbeeba1f18119655d320343ea9007752e
font_01_sfnt_off0000e628.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE628 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000fe3a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFE3A 17764 bytes
SHA-256: 2d704d0a46c1e26e3d3b8131ff181db7600e80f7ed4596b5e241621e27f9d290