Malicious PDF — malware analysis report

Static analysis result for SHA-256 81868115c611735c…

MALICIOUS

PDF

75.6 KB Created: 2021-09-05 19:22:48 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: 438d73b1771d93c0fb1df1e3f9adaab4 SHA-1: eb76ca2ae3d1867afac86e0914260543f518fe8a SHA-256: 81868115c611735cfe49553d345c78f7a83e698606a1abe10fe946dc29f14e1c
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF file was flagged by multiple heuristics and a machine learning classifier as malicious, with ClamAV identifying it as a phishing trojan. The document contains a link farm pointing to numerous domains, many of which appear to be compromised WordPress sites or disposable hosting, suggesting an attempt to distribute malicious content or phish for information. No scripts were extracted, but the presence of numerous external URIs indicates a strong likelihood of redirection to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9939

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://garglob.ru/uplcv?utm_term=reading+comprehension+exercises+3o+eso+pdf PDF link annotation
    • https://travelsafeway.com/userfiles/file/jozudelakad.pdfIn PDF document text
    • http://reelproductionshd.com/userfiles/file/99336457298.pdfIn PDF document text
    • http://www.jhannahs.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b80f4cd007e---sudifenere.pdfIn PDF document text
    • http://langeline.com/ckeditor/upload/files/xofegawesap.pdfIn PDF document text
    • http://allaboutdowney.com/userimages/pexaridoji.pdfIn PDF document text
    • https://xn----8sbaavnccwq4am.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/664d2dc4df5e03932661acc7192e53e8/letavomud.pdfIn PDF document text
    • http://summithighschool1958.com/clients/71652/File/85272816411.pdfIn PDF document text
    • https://nam.it/wp-content/plugins/formcraft/file-upload/server/content/files/160834842cdb16---kijovebidaseraxib.pdfIn PDF document text
    • https://gkatsov.com/userfiles/file/6489727110.pdfIn PDF document text
    • http://prodesign31.ru/wp-content/plugins/formcraft/file-upload/server/content/files/16104fb7a9a213---62824628540.pdfIn PDF document text
    • https://newat.ru/wp-content/plugins/super-forms/uploads/php/files/5a7c9e8cd3abfad3451beb7a4662c008/69837917214.pdfIn PDF document text
    • http://bjaimama.com/data/upload/2021/06/file/202106281906203575.pdfIn PDF document text
    • https://memoservicesrl.it/file/vefesa.pdfIn PDF document text
    • http://suachuabaoduongmaynenkhi.com/img_quanganh/files/pobapirafugubofil.pdfIn PDF document text
    • https://www.ccps.mx/wp-content/plugins/super-forms/uploads/php/files/7f1488fc7f74b109003510c3880ef9b3/64202645787.pdfIn PDF document text
    • http://cargo3030.ru/wp-content/plugins/formcraft/file-upload/server/content/files/1611e5e1255e6e---63869454704.pdfIn PDF document text
    • https://kaowei.tw/image/files/20210727_223443.pdfIn PDF document text
    • http://vervesimuhub.com/userfiles/file/wetut.pdfIn PDF document text
    • http://studioscoponi.eu/userfiles/files/fevikigabijefibexazuki.pdfIn PDF document text
    • http://zbraneklapka.cz/ckfinder/userfiles/files/vagakixadepenitox.pdfIn PDF document text
    • https://thewaves.net/wp-content/plugins/super-forms/uploads/php/files/0msesmvp2l5vcdd10sv0rseqph/nidifulolaxapojonir.pdfIn PDF document text
    • http://whewfamily.com/clients/12004/File/luvijejizasasi.pdfIn PDF document text
    • https://www.superioreagle.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c15950c86bb---xawumadobewupu.pdfIn PDF document text
    • http://english-island.pl/wp-content/plugins/super-forms/uploads/php/files/jjjtmh68kameev4rkvq9nq77s7/66783503658.pdfIn PDF document text
    • http://webscape.co.bw/wp-content/plugins/formcraft/file-upload/server/content/files/16070e14a472c7---62042750346.pdfIn PDF document text
    • http://www.nowsingapore.co.id/wp-content/plugins/formcraft/file-upload/server/content/files/160bea9cac8f4f---17807075486.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_off0000c165.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC165 17652 bytes
SHA-256: b3a47ffe7fdc2957dcd7798bde11a3b2c5fbb231485751a3f49db235dec25a64
font_01_sfnt_off0000ee94.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEE94 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000106ab.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x106AB 11240 bytes
SHA-256: f1bbf1d9a3f12baa84c0fc70d882f81b18008a4f650ab3dc2569eab13791e845