Malicious PDF — malware analysis report

Static analysis result for SHA-256 88a0f3c1df9d4300…

MALICIOUS

PDF

74.8 KB Created: 2021-05-28 11:22:45 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-27
MD5: ff3b9ac1072b4b017aa78d5d8cfaab0d SHA-1: e0ec3c453d20f2147ac757b33d3bb3eef6f48ac0 SHA-256: 88a0f3c1df9d43007de298dc0f641f67cfe5b2e916e38bec253abbaf6ceaf066
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It contains a link farm with numerous URLs, many hosted on compromised WordPress sites, suggesting a phishing or malware distribution campaign. The presence of external URIs and the overall structure point towards a spearphishing attachment attack vector.

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 https://infrive.ru/uplcv?utm_term=hungry+shark+mod+apk+download+free PDF link annotation
    • http://paymentsbusiness.ca/wp-content/plugins/formcraft/file-upload/server/content/files/1609d32a9f3f2d---2757034680.pdfIn PDF document text
    • https://www.certificagreen.com/wp-content/plugins/formcraft/file-upload/server/content/files/160984ce38e89f---lefitozulovuremekasuli.pdfIn PDF document text
    • https://staffxrecruitment.com/wp-content/plugins/super-forms/uploads/php/files/7cf95f1fa3e84f86233f1f828a293c84/51325660517.pdfIn PDF document text
    • http://krindustria.com.br/site/wp-content/plugins/formcraft/file-upload/server/content/files/160a85b9a37963---pivusijilotevati.pdfIn PDF document text
    • https://popa.com.br/wp-content/plugins/super-forms/uploads/php/files/dfb0f59a715deb6d2940ce8adc7c4ed1/zedofoworeresij.pdfIn PDF document text
    • http://billedbutikken.dk/articlefiles/file/netevezilugolo.pdfIn PDF document text
    • http://traditionsradio.com/wp-content/plugins/super-forms/uploads/php/files/jrcm08a979rr9o7g9ava9midn6/fewamawexogetijeju.pdfIn PDF document text
    • https://www.frankreich-ferien.ch/wp-content/plugins/formcraft/file-upload/server/content/files/160aa891056606---digemafopalo.pdfIn PDF document text
    • https://camile.vn/wp-content/plugins/super-forms/uploads/php/files/esif7ni60v98vih1459lh2n0m4/73908083735.pdfIn PDF document text
    • https://www.varishastalari.com/wp-content/plugins/formcraft/file-upload/server/content/files/160860a6c2893d---powegewopapux.pdfIn PDF document text
    • https://utilitydiscount.com/wp-content/plugins/formcraft/file-upload/server/content/files/16099cb0469035---kulezojewogidow.pdfIn PDF document text
    • https://www.eoluk.com/wp-content/plugins/super-forms/uploads/php/files/3nr516as3fsd08ihip9aiba5fe/murasimedotawifipinav.pdfIn PDF document text
    • https://ivfnna.gr/wp-content/plugins/super-forms/uploads/php/files/6a7a4e7dde328517f3edd7fbaf170410/sogesufojiwenuzedaxegudar.pdfIn PDF document text
    • http://amphorabeautyclub.com/campannas/file/disojudalis.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn 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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000e5b2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE5B2 5672 bytes
SHA-256: 124b1aca8bbe951e254a9f38dfba91c1ffc8ea54c8abbb701e1304ed4b2c9c3e
font_01_sfnt_off0000f8f8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF8F8 10932 bytes
SHA-256: df42468ae532d7103617577d58091fccf77f0252009e2b493065408d7191bed4