Malicious PDF — malware analysis report

Static analysis result for SHA-256 66aed6f3b3df2657…

MALICIOUS

PDF

75.0 KB Created: 2021-05-17 07:18:51 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-16
MD5: bd957dd9470d8e01402a435b93d86149 SHA-1: 093de62ffb00ba40b13396e155a61cb2531b1e66 SHA-256: 66aed6f3b3df26570bfe99f48a9d20d3941f8d4ccdb02d96059a2544e3df59a7
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 ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It contains numerous external links, many pointing to compromised WordPress sites, suggesting it functions as a link farm to distribute further malicious content or phish users. The presence of multiple distinct hosts and the use of 'utm_term' parameters in some URLs further support the link farm and potential phishing or SEO poisoning attack pattern.

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://synerhu.ru/uplcv?utm_term=bematech+lr2000+pdf PDF link annotation
    • https://lakeshoresmilesdentistry.com/wp-content/plugins/super-forms/uploads/php/files/24mrkl6aertik7eesjtrkhg1j5/morexipun.pdfIn PDF document text
    • https://myphi.biz/nbloom/fckuploads/file/lademaveli.pdfIn PDF document text
    • https://www.rockfallco.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606f0f0dd7eba---46614417067.pdfIn PDF document text
    • https://movesforfree.com/wp-content/plugins/super-forms/uploads/php/files/bq2ft6ml29bpbsb9fnb6684gl4/filalafarak.pdfIn PDF document text
    • http://cameronhaddock.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606cf92fcafef---daxebenilawad.pdfIn PDF document text
    • https://salubrismd.com/wp-content/plugins/super-forms/uploads/php/files/071eab8ecb0dc7b35b0d5e8a861b820c/tidivazujireletegotor.pdfIn PDF document text
    • https://www.uniqueartzz.com/wp-content/plugins/super-forms/uploads/php/files/pctuuo5724m7bm8buf8gfauvru/sigisutebexagipisej.pdfIn PDF document text
    • http://whalesart.com/uploadfile/file/%5C/2021051618563944.pdfIn PDF document text
    • https://costumeworld.com/wp-content/plugins/formcraft/file-upload/server/content/files/16070b538b8892---wibunabigifozinofokonasot.pdfIn PDF document text
    • https://allianceflooring.net/wp-content/plugins/super-forms/uploads/php/files/68bf56c8f443bb0b32daf82966195ab3/78198731926.pdfIn PDF document text
    • https://www.lang-mayer.de/wp-content/plugins/formcraft/file-upload/server/content/files/160845425620c0---darusez.pdfIn PDF document text
    • https://genesislighting.net/wp-content/plugins/super-forms/uploads/php/files/3cd7601dbbdee4c7844129e8039aea3f/63018236718.pdfIn PDF document text
    • https://rlvanstory.com/wp-content/plugins/super-forms/uploads/php/files/323fe12b437d185a13073876c8c93cdb/logunetijaroredebisije.pdfIn PDF document text
    • http://skuplaptop.pl/wp-content/plugins/formcraft/file-upload/server/content/files/160788bfda2d55---wojapik.pdfIn PDF document text
    • https://www.m2asolutions.com/wp-content/plugins/super-forms/uploads/php/files/05916ae96452aa42a1ae73c6f6481367/88792539247.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
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000d085.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD085 5540 bytes
SHA-256: bc03d6bbbe69aa153199ad78409c14b302dd2052e38a99a4d88a5c8235f80c91
font_01_sfnt_off0000e32e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE32E 11388 bytes
SHA-256: 73db3d6dae19f732ef6f5b2069a6d1fff740c167559f3b338c743fb60150fd55
font_02_sfnt_off000109de.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x109DE 16200 bytes
SHA-256: ab31bad50d1fabf409272c8d40ebe0962ad1e89052e15148f5d4edc4e75f9fc9