Malicious PDF — malware analysis report

Static analysis result for SHA-256 05c5b9b55e94cf7f…

MALICIOUS

PDF

74.4 KB Created: 2021-09-19 03:58:07 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 2ff049596ac915ca8dbf59fe9258d2af SHA-1: 67e427eded25f7d90eb275a29b6ae22341874a8f SHA-256: 05c5b9b55e94cf7f41a8f076797e6277829a3039fb0d506cc08014d354ab5504
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF file was identified as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. Heuristics reveal it functions as a link farm, with numerous URLs pointing to potentially compromised or disposable hosting, suggesting a phishing or malware distribution scheme. The presence of external URIs and link farm indicators strongly supports this attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9953

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 http://www.consorcio.edu.pe/wp-content/plugins/formcraft/file-upload/server/content/files/161465993db962---xofenivu.pdf
    • http://xn--80ackbssfuieecff0e8c.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/8l5e5bhe3ihopsa4spajlm85j5/tibuvuniga.pdf
    • http://zovsh.com/Uploadfiles/files/melinir.pdf
    • https://egc.ecrom.work/syo/files/25253950304.pdf
    • http://gonganmi.com/userfiles/file/40028108386.pdf
    • https://www.colline-eternelle.com/ckfinder/userfiles/files/68613207674.pdf
    • http://beta-rc.com/upload/files/64968740151.pdf
    • http://xaydungphongphu.com/uploads/files/zuzututejepikusomesidi.pdf
    • http://ambvetesopo.eu/userfiles/files/tudad.pdf
    • http://tavio.su/files/file/sexedawawikibatu.pdf
    • http://oodow.cn/upload/file/210911214639151597gbfg7jzupti9.pdf
    • https://ag-concept.ru/wp-content/plugins/super-forms/uploads/php/files/24f5768a482e01ab041b7ea2cae487fd/xuzuredulijexajuve.pdf
    • http://okna-kurska.ru/page_edit/_samples/userfiles/files/60454522336.pdf
    • https://www.studioline.ie/ckfinder/userfiles/files/tilibizawegukogefufaned.pdf
    • https://www.grandiosa.is/wp-content/plugins/super-forms/uploads/php/files/tq4710knlu4j6f9cgo1im06dt7/nosijujejezawobagufan.pdf
    • http://thankschicken.com/uploads/files/59270073618.pdf
    • http://xn----ctbguteehkho5h.xn--p1ai/ckfinder/userfiles/files/52292150666.pdf
    • http://transcash.com/ci/userfiles/files/79676595925.pdf
    • https://regenerativetherapyforpain.com/wp-content/plugins/super-forms/uploads/php/files/5472bccaf04d5e86db8550361d7bcb15/64549120399.pdf
    • http://aven.su/userfiles/file/61154109018.pdf
    • http://itkaufmann.com/images/fckimages/file/bakilijusu.pdf
    • http://skupka23.ru/upload/m/91923246899.pdf
    • http://pretaporter-pegah.com/userfiles/file/9343625423.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/1xuhb7AK25c/uplcv?utm_term=smith+organic+chemistry+5th+edition+solution+pdf
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000bc3b.bin
2c2fade18b4b7568aa3818d7b1cdf1c18ff8a98f9bfb8e8e89d6733d91a06b01
pdf-font-stream PDF embedded font (sfnt) at offset 0xBC3B 11492 bytes
font_01_sfnt_off0000d714.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xD714 16792 bytes
font_02_sfnt_off0000ef26.bin
5e0b86e61f3a0d9eb515d198f98b0994817a8b7f498f6610c04f0d8f73185f56
pdf-font-stream PDF embedded font (sfnt) at offset 0xEF26 17344 bytes