Malicious PDF — malware analysis report

Static analysis result for SHA-256 4a5b88f5db8acea3…

MALICIOUS

PDF

80.8 KB Created: 2021-09-18 12:34:56 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 97fdef089a1466a2c8eaf56fee4c3c30 SHA-1: 97ad6d3af390693b997d06366ec3c98ae85efe7b SHA-256: 4a5b88f5db8acea3030aef674abedf3eaf692866370f6eaf55bb028c5653aabe
156 Risk Score

Malware Insights

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

The PDF file was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, directing users to multiple external URLs, some hosted on compromised CMS platforms or disposable domains. The embedded URLs, such as http://xhzhengli.com/upload/jasurododapapukonuje.pdf, are likely part of this malicious redirection scheme.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9972

Heuristics 6

  • 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.
  • 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://xhzhengli.com/upload/jasurododapapukonuje.pdf In PDF document text
    • http://bephoangdung.vn/uploads/ckfinder/files/ragopatutapadowalel.pdfIn PDF document text
    • https://www.carlosfunes.es/wp-content/plugins/formcraft/file-upload/server/content/files/16136b35b32738---nonizupufumepenasare.pdfIn PDF document text
    • http://dtyxbpzx.com/filespath/files/20210918130139.pdfIn PDF document text
    • http://bhhangkhong.com/upload/images/files/81563719734.pdfIn PDF document text
    • https://abofahed.com/userfiles/file/nepesorudawowusuwana.pdfIn PDF document text
    • http://studiomanzetti.it/userfiles/files/46652992702.pdfIn PDF document text
    • http://daechienglishpark.com/ckfinder/userfiles/files/pizuvagovimugeribowotu.pdfIn PDF document text
    • http://akvatoria.by/UserFiles/files/zugipaputirebotun.pdfIn PDF document text
    • https://alismobile.co.uk/wp-content/plugins/super-forms/uploads/php/files/21e86891348972b4c28c6e301d66f346/rufojepuxomalobim.pdfIn PDF document text
    • http://studioriggio.it/userfiles/files/tetofavabulejejilos.pdfIn PDF document text
    • https://beytarimcilik.com/admin/editor_resim/file/23849607493.pdfIn PDF document text
    • http://hzqljsj.com/images/upload/File/41650812702.pdfIn PDF document text
    • http://dabien.co.kr/wp-content/plugins/formcraft/file-upload/server/content/files/1614522f758142---81185323806.pdfIn PDF document text
    • http://ud2-140.com/files/gizikilunizakimuvozu.pdfIn PDF document text
    • http://superlitefan.com/uploads/files/funobowurenedasej.pdfIn PDF document text
    • http://scantech3d.com/files/84621349390.pdfIn PDF document text
    • http://gourmethousemacau.com/UploadFilesfile///tagakugiwipu.pdfIn PDF document text
    • http://gsoam.ge/wp-content/plugins/formcraft/file-upload/server/content/files/16133972025f50---64824620986.pdfIn PDF document text
    • http://jinruily.com/UploadFile/file/20210908124718804.pdfIn PDF document text
    • https://copacndg.com/images/uploads/files/93969846517.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/A3Ryygt5BCM/uplcv?utm_term=how+to+earn+pokecoins+for+freePDF 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_off0000d67a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD67A 10596 bytes
SHA-256: 7ca817349d57d62d8ef5b78b0e2715c0c60aa80ab1abdf4d8f69ffcb329d6412
font_01_sfnt_off0000eedb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEEDB 18040 bytes
SHA-256: 829102c35cac9e1b07fd4369969d1a51d18210abbf6e45e70e76c2cbe1039ca7
font_02_sfnt_off00011d8f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11D8F 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1