Malicious PDF — malware analysis report

Static analysis result for SHA-256 551e3a8d7119d0c1…

MALICIOUS

PDF

74.1 KB Created: 2021-06-11 05:38:47 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-02
MD5: 444ae049d6826cbd40eab0ea43e489c5 SHA-1: 1c9cc3513248b1e4a13e928f3baa4fb463498112 SHA-256: 551e3a8d7119d0c1940a6347a3a146d1626cd25ecdcd9e2d38ea01a6dab34fe1
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. It uses a LOLBin command-execution lure. 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 0.9998

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
  • LOLBin token sequence in document text high SE_LOLBIN_RUN_COMMAND
    Extracted document text contains a Windows script/execution tool name (PowerShell, mshta, cmd, rundll32, regsvr32, …) within 220 characters of a dangerous flag, command verb, or URL. This is a visible 'run this' instruction in HTML/PDF/RTF lure bodies, or — in macro-laden Office files — the macro's own string-pool entries appearing adjacent in extracted text.
  • 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=unbeatable+top+town+hall+6+base PDF link annotation
    • https://goldenparadisestsimons.com/wp-content/plugins/super-forms/uploads/php/files/b2ffe9ff58336a6f30334db2577574bc/25616796263.pdfIn PDF document text
    • https://abeess.com/userfiles/file/26230954509.pdfIn PDF document text
    • https://brandonsmilesdentistry.com/wp-content/plugins/super-forms/uploads/php/files/7urn7k80lckudsshi609v695t4/dafat.pdfIn PDF document text
    • http://nd-58.ru/wp-content/plugins/super-forms/uploads/php/files/eabdd1ca4434c3282adfca3c9138631f/wazabuwanokogopasizo.pdfIn PDF document text
    • http://beergolfers.com./blog/images/file/27385148345.pdfIn PDF document text
    • https://eyestech.in/wp-content/plugins/super-forms/uploads/php/files/cpu3m6oucv8hgdcuel2trur4o9/15939446404.pdfIn PDF document text
    • http://hersheyhigh1981.com/clients/37302/File/gebabizewuwabojo.pdfIn PDF document text
    • https://cosalesrep.com/wp-content/plugins/super-forms/uploads/php/files/c624838de71eba1b18d9597d8cebb9d9/75022644805.pdfIn PDF document text
    • http://biomassasia.net/data_ed/userfiles/file/3396902670.pdfIn PDF document text
    • http://sns.hu/_user/file/sobisiwobemidupamilogij.pdfIn PDF document text
    • https://daluxerealty.com/wp-content/plugins/super-forms/uploads/php/files/kabvj7k43kqvpcmdhdrnml02i4/33527907699.pdfIn PDF document text
    • https://www.hagensmarketing.com/wp-content/plugins/formcraft/file-upload/server/content/files/16087a4ec4cfe7---58971725437.pdfIn PDF document text
    • https://prikolnaya.com/wp-content/plugins/super-forms/uploads/php/files/77b6ee1590d54a0582e6fb43700db2f0/73011443695.pdfIn PDF document text
    • https://www.hagensmarketing.coIn macro / runtime command snippet
    • 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_off0000e4c8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE4C8 5188 bytes
SHA-256: b67ea546e058a5beefeb10d907d6e1928fb7c2a8c893f3553289f56b51149042
font_01_sfnt_off0000f680.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF680 11028 bytes
SHA-256: 5a80c1e2f710cd6273103d4ea495f25ad4dde5681ef590ccf2551b58c5a3741b