Malicious PDF — malware analysis report

Static analysis result for SHA-256 5110d4b2b33c1c91…

MALICIOUS

PDF

81.6 KB Created: 2021-06-09 06:24:29 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-25
MD5: 61b1299238d34aa901730f1917c8da69 SHA-1: 23c431bec691addfb642ddfe34efebf0456fcf80 SHA-256: 5110d4b2b33c1c91b9c19aa5fa645fc18c080082dd12b84043fe7f2b744c8020
196 Risk Score

Malware Insights

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

This PDF document was flagged as malicious by ClamAV and an ML classifier. The file embeds a large number of external links characteristic of an SEO link farm, many hosted on compromised CMS upload directories. Specific URLs and indicators for this sample are listed in the indicators section.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9995

Heuristics 7

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • PDF link to algorithmically-generated URL high PDF_RANDOM_URL_LINK
    PDF contains a clickable HTTP(S) link whose host looks algorithmically generated (pronounceable-random labels) and whose path/query carries a long high-entropy token. This is the randomized-redirector pattern of malspam phishing lures — the visible document is only a prompt — not a PDF parser vulnerability.
  • 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://oniceh.ru/uplcv?utm_term=gta+san+andreas+free+download+for+windows+7 PDF link annotation
    • http://opalbiosciences.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609b202966c2d---31444289308.pdfIn PDF document text
    • https://www.proctoloji.com/wp-content/plugins/formcraft/file-upload/server/content/files/16079c2ebeeb43---61984911901.pdfIn PDF document text
    • https://virtualpulse.eu/UserFiles/file/74250789264.pdfIn PDF document text
    • https://avenirpourtous.fr/wp-content/plugins/formcraft/file-upload/server/content/files/16094bd06620b9---66133371773.pdfIn PDF document text
    • https://emmaushuis.org/pages/56431383925.pdfIn PDF document text
    • https://www.novet.de/wp-content/plugins/formcraft/file-upload/server/content/files/16084417b4784a---losupideja.pdfIn PDF document text
    • http://wenxuezj.com/images/File/povejajejizozujinu.pdfIn PDF document text
    • http://www.fullertherapy.com/wp-content/plugins/formcraft/file-upload/server/content/files/160842fd01cef4---zefuxefipekonamekowinife.pdfIn PDF document text
    • http://xn--aknmedikal-yub.com/uploads/file/takemogolop.pdfIn PDF document text
    • https://absolut-fit-and-dance.de/wp-content/plugins/super-forms/uploads/php/files/44hu0us5932lub4sjbme661ffh/delurodenapo.pdfIn PDF document text
    • http://www.sunarnuricomuisvealisverismerkezi.com/wp-content/plugins/super-forms/uploads/php/files/letm8vbekq2tqrtpal915p6982/vewelaviwiv.pdfIn PDF document text
    • http://ankurgroups.com/userfiles/file/mijojonaxono.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://www.daltonmaag.com/In 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 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000eba0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEBA0 3080 bytes
SHA-256: 3b6c3edccbbdf68622c80e44ac099bd4bffa00507f4f1bc839f0bdbf087aa810
font_01_sfnt_off0000f6aa.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF6AA 4892 bytes
SHA-256: 9cca4fa94a9b915ee2a5ac2d4fb81abce19b9aa3b9192bfc487374ac9a77178a
font_02_sfnt_off00010773.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10773 10424 bytes
SHA-256: 86180724e30be742c034b683513dba0e6dc3f67ffb9c284061c77262611f822c
font_03_sfnt_off00012a91.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12A91 4324 bytes
SHA-256: cd94ef65598b1866d0653cdd88243d989fd81359c0e770c2d3a4858f1c2f6d34