Malicious PDF — malware analysis report

Static analysis result for SHA-256 8acb9727d4347fb4…

MALICIOUS

PDF

70.8 KB Created: 2021-05-28 08:08:49 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-24
MD5: 83a0b727e9493517183463248c4b491b SHA-1: ac0e7cd9002be7e4cb2de8ad1a6fcd3b4ad17a10 SHA-256: 8acb9727d4347fb4d550a3ae23be5e242c095c541c31bc016750cce0854ea798
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. Heuristics identified it as a link farm hosted on compromised CMS upload directories, pointing to multiple suspicious PDF files. The document body, though partially garbled, suggests a lure related to 'arquivo formato xml', likely a pretext to direct users to these malicious links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

Heuristics 6

  • 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 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://artsketch.ru/wp-content/plugins/super-forms/uploads/php/files/a94de4fa0460c7e3b5f0dfa35825f592/pelumetexuma.pdf In PDF document text
    • https://www.truesdalepainting.com/wp-content/plugins/formcraft/file-upload/server/content/files/16078db5fdab2b---nisiwopisodezerux.pdfIn PDF document text
    • https://greyquotient.com/wp-content/plugins/super-forms/uploads/php/files/25ef19ac9e2748a7ddd3d05d0b538951/lejog.pdfIn PDF document text
    • http://baigeleather.com/userfiles/file/kularigig.pdfIn PDF document text
    • https://samiznojmo.cz/wp-content/plugins/super-forms/uploads/php/files/cb588b4eaa2ecf359983225ade7a9498/90479340320.pdfIn PDF document text
    • https://roweryelectra.eu/app/webroot/uploads/file/16199786305373.pdfIn PDF document text
    • http://www.gaviprintpack.com/wp-content/plugins/formcraft/file-upload/server/content/files/160aa9e76eb763---43433623068.pdfIn PDF document text
    • https://inclinedigital.com/wp-content/plugins/formcraft/file-upload/server/content/files/160af23385db10---72407667418.pdfIn PDF document text
    • http://bostonmentors.com/userfiles/file/54170449422.pdfIn PDF document text
    • https://fitnessrev.net/wp-content/plugins/super-forms/uploads/php/files/8dt6jqnc0850rcfadhrdi55dpq/24543304835.pdfIn PDF document text
    • http://www.molinoag.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608d721091837---10182640098.pdfIn PDF document text
    • https://www.enterpriselighting.com/wp-content/plugins/super-forms/uploads/php/files/0c2aea59efe627e86edcc3a5ec859841/61673104371.pdfIn PDF document text
    • https://irisapp.cn/uploadfiles/fckeditor/20210515/file/16210513019168.pdfIn PDF document text
    • http://www.associatedomains.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a79b0aeb988---98743928257.pdfIn PDF document text
    • http://www.combatsim.eu/wp-content/plugins/formcraft/file-upload/server/content/files/16080eb945897d---37028916490.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/1eyvgo/aqOO/~3/1xuhb7AK25c/uplcv?utm_term=o+que+%25C3%25A9+arquivo+formato+xmlPDF 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_off0000d651.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD651 5156 bytes
SHA-256: 2ef5056b71592f569bb9e696170bf0ebd49f5cea86707000d60eb2fb105072fa
font_01_sfnt_off0000e790.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE790 12204 bytes
SHA-256: d10a32377d0bcb13d16082d7811b8ae5cda574df4a2b27c0d24c78f494f1a674