Malicious PDF — malware analysis report

Static analysis result for SHA-256 011a829ea769d1d6…

MALICIOUS

PDF

87.9 KB Created: 2021-09-11 09:01:51 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: c3b6884f846a595aea10c1d9e6af3e77 SHA-1: 953cdd02672819825183a1f3333f1ae848dbcadc SHA-256: 011a829ea769d1d63e70248ec21dcf89cc24e6b3493a355abf326cb13f7540b7
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file is identified as malicious by ML classifiers and ClamAV, with multiple heuristics indicating it functions as a link farm. The PDF contains numerous external URIs, including those hosted on compromised WordPress sites and disposable domains, suggesting an attempt to redirect users to malicious content. The presence of embedded URLs and the overall structure point towards a phishing or malware distribution scheme.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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://laborke.ru/uplcv?utm_term=watch+a+cinderella+story+once+upon+a+song+free
    • https://nexusmediation.nl/files/76173319535.pdf
    • http://dejede.com/userfiles/file/xiborifovukedofiw.pdf
    • https://law.myvzl.com/wp-content/plugins/super-forms/uploads/php/files/2h8ccnu2edfo9escpjpmk6vm8m/10644145413.pdf
    • https://skillmapmagazine.com/ckfinder/userfiles/files/49615233893.pdf
    • http://hitmet.slektenkaas.com/bilder/file/liwisuvekinunudider.pdf
    • http://nerezove-kuchyne.cz/UserFiles/File/52927664222.pdf
    • https://marosme.ro/hirek/file/rewurebumubogipopazufi.pdf
    • https://asiapharma.la/files/files/wutiwadedidapuwa.pdf
    • http://dobraukraina.org/sites/all/sites/dobraukraina.org/files/6128703500.pdf
    • https://gornjastubica.hr/files/wodovazezoroditegeren.pdf
    • https://fertilizerproductionprocess.com/d/files/12949370029.pdf
    • http://bakefruit.com/uploads/files/202109080410581581.pdf
    • http://holzweiss.at/ratifiderozegixofa.pdf
    • http://borik.customreal.sk/data/files/nejumiwikazototimasekix.pdf
    • http://sensor4you.com/fckeditor/editor/filemanager/connectors/php/fckeditor/upload/202109/file/sizavixag.pdf
    • http://www.saraviation.com/wp-content/plugins/formcraft/file-upload/server/content/files/16131f20c58851---62716881420.pdf
    • https://komunalno-vrgorac.hr/files/favetoregozawizalodu.pdf
    • http://billedbutikken.dk/articlefiles/file/tolisufamubozotudowu.pdf
    • http://dishandspoonproductions.com/ckfinder/userfiles/files/wasidibebexelupovumer.pdf
    • https://newtech-utm.pl/userfiles/file/38553890412.pdf
    • http://yingtailong.com/upload/file/210901165844518564n1x2243mn18d.pdf
    • https://www.caesarstravel.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612ee8ce38a64---79270225918.pdf
    • http://synowka.pl/galeria/file/37248022882.pdf
    • https://artbynela.com/uploads/file/27056251902.pdf
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000f4e1.bin
a64b50ba9bc93bb5eb38753b904ec5a95a1158b880bc2b653a2c006f81b0a162
pdf-font-stream PDF embedded font (sfnt) at offset 0xF4E1 16572 bytes
font_01_sfnt_off00011fcd.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x11FCD 16792 bytes
font_02_sfnt_off000137e4.bin
109ef19b0dccc07f2db0f623bde037e1d4a5df6dede02092ec177410ed728442
pdf-font-stream PDF embedded font (sfnt) at offset 0x137E4 11108 bytes