Malicious PDF — malware analysis report

Static analysis result for SHA-256 5c6f6af3a8b91dd1…

MALICIOUS

PDF

71.6 KB Created: 2021-04-28 11:26:43 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-05-22
MD5: 010096b827053558ef92ea09beb3c249 SHA-1: 5781192b9706dedce1a2dc082d9206c76ae5d3f7 SHA-256: 5c6f6af3a8b91dd1e06bfbfa7678a556bb42b66cee0e98f1eba3325fdd4cd3d0
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF file was detected as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. Heuristics identified it as a link farm pointing to compromised WordPress upload storage and disposable hosting, suggesting it's designed to redirect users to malicious sites. The embedded URLs and the nature of the heuristics strongly suggest a phishing or malware distribution campaign.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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 http://protech.com.ng/wp-content/plugins/formcraft/file-upload/server/content/files/160790ef5e5e2a---dovomixe.pdf In PDF document text
    • https://lightingsystemscol.com/wp-content/plugins/super-forms/uploads/php/files/4e0e37c3d16859859e61e93abcdfda89/58569387613.pdfIn PDF document text
    • https://alenakovalchuk.ru/wp-content/plugins/super-forms/uploads/php/files/cb976d2ea1ddda85be38b1a8e5730165/34604458990.pdfIn PDF document text
    • https://xn--80aaaglcftt5alesfkk7f.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/17f710880b7f62dd3dbe8108ed0f1f49/29164007520.pdfIn PDF document text
    • https://auf.vn/wp-content/plugins/super-forms/uploads/php/files/1g0eth7acfi3cjvngr5ph6jj80/98913146626.pdfIn PDF document text
    • https://adepotcustom.com/UploadFiles/file/20210428081653123.pdfIn PDF document text
    • http://jointrilogy.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608790ae12770---sisuxibete.pdfIn PDF document text
    • http://vibrosystem.ro/wp-content/plugins/formcraft/file-upload/server/content/files/160757c51374cb---sudonibilisubomuxeruwusi.pdfIn PDF document text
    • https://joyfool.art/wp-content/plugins/super-forms/uploads/php/files/b3ee59b420f81c7e4330150b6eb39154/duxajoluj.pdfIn PDF document text
    • https://retentionstudentexperience.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607d10548f7ae---vutiref.pdfIn PDF document text
    • http://www.telsercom.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607d64462fbe4---90838882023.pdfIn PDF document text
    • http://www.brennholz-heinlein.de/wp-content/plugins/formcraft/file-upload/server/content/files/1607ef00981261---wowutito.pdfIn PDF document text
    • http://www.ellisrasbetonwerke.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/1608431085c60c---28175444344.pdfIn PDF document text
    • https://master.plus/wp-content/plugins/super-forms/uploads/php/files/4a0089d4b544f45b8421c08db5b0d0c3/46846830825.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=android+apps+on+windows+10+softwarePDF 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_off0000da89.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDA89 5276 bytes
SHA-256: ad51f06bbcb74c2bc16b29478dc9c829d214438a056f94ec914fc565922af7cf
font_01_sfnt_off0000eca1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xECA1 10780 bytes
SHA-256: fc466d4abca16792179d577257c691ae8f38b8055e1faff869d067f730b8f2be