Malicious PDF — malware analysis report

Static analysis result for SHA-256 4f9c362addd87ea3…

MALICIOUS

PDF

67.3 KB Created: 2021-06-22 23:32:59 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-14
MD5: d976961bd075c0728d30ceca7782ab70 SHA-1: 634334203e46bf7457ac42b6a7e86e09358f4f1e SHA-256: 4f9c362addd87ea30aa9a11005f57b28d90104d316a5aa2a46733757c2dbcccc
164 Risk Score

Malware Insights

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

This PDF file was flagged by a machine learning classifier and ClamAV as malicious, indicating a high likelihood of malicious intent. It contains a link farm pointing to compromised WordPress upload directories, suggesting it's designed to trick users into downloading further malicious content. The presence of multiple distinct hosts hosting similar PDF files reinforces the link farm tactic.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

Heuristics 7

  • 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.
  • Visual download / call-to-action button lure low SE_DOWNLOAD_BUTTON
    Document contains a call-to-action phrase ('Click here to download', 'Download Now', etc.) — low-signal unless other findings point to a malicious workflow
  • 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://xn--1--8kcai1ck2bs.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/14defcc7c89d84114226b4e6996842bd/tezan.pdf In PDF document text
    • https://naseeha.org/wp-content/plugins/super-forms/uploads/php/files/95467aca55dfa887c6955fa52edbacae/6097617851.pdfIn PDF document text
    • https://foxtailmag.net/wp-content/plugins/super-forms/uploads/php/files/a53c37d25f5a8376bb27b744139d2492/nejowene.pdfIn PDF document text
    • http://essiac.cz/UserFiles/file/1935497755.pdfIn PDF document text
    • https://nhaban24h.com.vn/wp-content/plugins/super-forms/uploads/php/files/nutitee2gt5j4i313jcvo0780h/1598432058.pdfIn PDF document text
    • https://dezsredstvompx.ru/wp-content/plugins/super-forms/uploads/php/files/14bebbda5d11ebde1a2d00e9bbf0dc49/53139543279.pdfIn PDF document text
    • https://webgirls-studio.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606d3aef9f6b6---bewosigepafirabofim.pdfIn PDF document text
    • http://www.guaitoli.eng.br/wp-content/plugins/formcraft/file-upload/server/content/files/1609829f89476e---xewirakujikoti.pdfIn PDF document text
    • http://www.tenniscanberra.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/1608f64b6b1132---25781677882.pdfIn PDF document text
    • https://arenda1s.ru/wp-content/plugins/super-forms/uploads/php/files/bd357aaaef3cbc79955b92db5b03eae7/87784379452.pdfIn PDF document text
    • https://spherule.org/wp-content/plugins/super-forms/uploads/php/files/5344af2d4f5f85ddf7ca5b9e433b766c/witimesukuwanuwafagedekum.pdfIn PDF document text
    • https://alignerco.com/wp-content/plugins/super-forms/uploads/php/files/d12c7f807262756dd6f96b957a2b324c/27228862768.pdfIn PDF document text
    • http://thestarbusan.net/FileData/ckfinder/files/20210605_789C746D727AF9A2.pdfIn PDF document text
    • https://directprocessors.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c405890dc01---24814238175.pdfIn PDF document text
    • http://romanakladatelstvi.cz/userfiles/file/33219326862.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/PmAiG5ZyT-k/uplcv?utm_term=java+database+interview+questionsPDF 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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000c6cf.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC6CF 5196 bytes
SHA-256: b10619d721a43995f453d445352534939ce154da3057c1a7f7cd5097e78cf1fd
font_01_sfnt_off0000d89a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD89A 11280 bytes
SHA-256: 1de470052a970aaefc4625dd5f6966bfd0d88712b551d396e20caa67f63e69bb