Malicious PDF — malware analysis report

Static analysis result for SHA-256 72526673b77ef52c…

MALICIOUS

PDF

77.9 KB Created: 2021-09-15 22:59:46 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 38af7559dd72553ac113949920197919 SHA-1: 688c8daf9dae5071f44445efaadbce1e2c807fb2 SHA-256: 72526673b77ef52c1ae655aefb76c90f36ac908ad7c77ed5f0b7f546a69e075f
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF 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 numerous distinct domains, with a high concentration of links on disposable hosting. While no scripts were directly extracted, the PDF structure and its nature as a link farm suggest it is designed to redirect users to malicious sites, likely for phishing or further malware delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://posicert.com/upload_fck/file/2021-9-11/20210911185522704353.pdf In PDF document text
    • http://bilateralmatters.org/userfiles/file/bugibevuxeduvum.pdfIn PDF document text
    • http://ex2010.com/uploadfile/file/2021091407561773499.pdfIn PDF document text
    • https://cafesca.mx/ckfinder/userfiles/files/71952589510.pdfIn PDF document text
    • http://cegled.varosom.hu/userfiles/files/revejinesugenokute.pdfIn PDF document text
    • https://laznia-radom.pl/userfiles/file/53874950914.pdfIn PDF document text
    • http://yamamatoen-wanwan.jp/ckfinder/userfiles/files/10635850186.pdfIn PDF document text
    • https://mimpiindah1.com/contents/files/xudoxe.pdfIn PDF document text
    • https://es21sys.com/userfiles/file/53519526175.pdfIn PDF document text
    • https://songiadahoaian.com/upload/ck/files/gululilimaziriwedaf.pdfIn PDF document text
    • https://onthespothousing.com/userfiles/file/91594382897.pdfIn PDF document text
    • http://malagi.pl/user-files/fck/file/33725665023.pdfIn PDF document text
    • http://kerekesvillszer.hu/UserFiles/file/fipajefesib.pdfIn PDF document text
    • https://luathoanghuy.com/uploads/files/guxizogujarazabo.pdfIn PDF document text
    • https://bokaichenyu.com/upload/files/befagufodewize.pdfIn PDF document text
    • https://repairbase.net/FCKeditor/editor/filemanager/connectors/php/images/file/kesawutonuzozuzezixira.pdfIn PDF document text
    • http://ldksolar-officialliquidation.com/userfiles/files/12916537687.pdfIn PDF document text
    • https://m-astar.com/UserFiles/files/65861005762.pdfIn PDF document text
    • http://makrostal.pl/user_images/file/22033837428.pdfIn PDF document text
    • http://koreaseals.com/ckfinder/userfiles/files/vokajiwolag.pdfIn PDF document text
    • http://hig-hegmann.de/userfiles/file/fubodinuranawuvi.pdfIn PDF document text
    • https://abcelectricalonlineshop.brilliantwebtech.com/userfiles/files/sosivumokuguje.pdfIn PDF document text
    • http://ctnphrae.com/ckfinder/userfiles/files/95774562712.pdfIn PDF document text
    • http://first-group.kr/ckupload/files/55933106476.pdfIn PDF document text
    • http://dsfly.com/uploads/files/46081769218.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/1KS0DP0cxss/uplcv?utm_term=vpn+panda+apkPDF 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_off0000ced7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCED7 9692 bytes
SHA-256: 35755d34c2e3d71ceedaf2404145527a45454b01915f7192cdb0dcfc568b2bfb
font_01_sfnt_off0000e3f9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE3F9 17676 bytes
SHA-256: 63e5a37a088d45c412d29b2f0674a3759fd71d58523d4420efd414e6c8cf57d9
font_02_sfnt_off0001120e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1120E 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1