Malicious PDF — malware analysis report

Static analysis result for SHA-256 31fd38b7b815cc25…

MALICIOUS

PDF

72.8 KB Created: 2021-06-13 12:09:49 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 02fe6dfa550ab6e8c0ec2a90e3a03522 SHA-1: 1f968cf9d269d63f2f750cb19cccfc65e941c891 SHA-256: 31fd38b7b815cc25af0f8dac928bba92cf05a829ef2c1dc44bafab92b9220c26
164 Risk Score

Malware Insights

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

The file was detected as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. The PDF contains numerous embedded URLs pointing to compromised WordPress sites and disposable hosting, suggesting a link farm designed to redirect users to malicious content. The presence of a 'download button' heuristic further supports the lure-based attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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 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.
  • Visual download / call-to-action button lure low SE_DOWNLOAD_BUTTON
    Document contains a call-to-action phrase ('Click here to download', 'Download Now', etc.) — low-signal unless other findings point to a malicious workflow
  • 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://laborke.ru/uplcv?utm_term=superlative+sentences+example
    • https://fermuar.com/wp-content/plugins/formcraft/file-upload/server/content/files/160871d588a888---lutilazajinumiz.pdf
    • http://www.saraviation.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c2fad9bf31d---26669854703.pdf
    • https://neavocats.com/wp-content/plugins/super-forms/uploads/php/files/1e64c17b413b778256c7806b8628cf30/16608249134.pdf
    • http://www.microsinusectomi.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606d7c3037b57---tafafoparuboj.pdf
    • https://sunarchegypt.com/userfiles/file/86813431089.pdf
    • http://cageart.ca/wp-content/plugins/formcraft/file-upload/server/content/files/16076927165da2---zetoj.pdf
    • https://www.pal-kont.hu/wp-content/plugins/super-forms/uploads/php/files/8d6df2e1003ec1d6f9aeb2e18c07a474/rebibasagureve.pdf
    • http://www.vivelamusica.es/wp-content/plugins/formcraft/file-upload/server/content/files/160927e0019026---tokonesolik.pdf
    • https://taxiparga.com/wp-content/plugins/super-forms/uploads/php/files/cd34eab740ce373a5b1b072e351182ed/sosufewasutu.pdf
    • https://www.toptalentusa.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a024d42e571---juxadumamoxipejowipubul.pdf
    • https://acornschoolcharleston.org/wp-content/plugins/super-forms/uploads/php/files/8473153d57b6317d69990aeb883b1f78/fekadavuj.pdf
    • https://inchirierielicopter.ro/wp-content/plugins/formcraft/file-upload/server/content/files/160830ac366a8c---sepavafepebanir.pdf
    • https://popcouncilinstitute.org/wp-content/plugins/super-forms/uploads/php/files/85f478360cd5fd5d0e67083601bcc698/72358930548.pdf
    • https://inlandautorepairmurrietaca.com/wp-content/plugins/super-forms/uploads/php/files/ebd50a5e1087be310f3e978907d42cb3/zazamanagonefinu.pdf
    • https://boldvision.tv/wp-content/plugins/formcraft/file-upload/server/content/files/160c099e195838---natabuxofo.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • 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://scripts.sil.org/OFL

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000df9a.bin
0388073f967a04f088391b1674e792940cd6e2e4fe0923dedd4306c78b9441f2
pdf-font-stream PDF embedded font (sfnt) at offset 0xDF9A 5308 bytes
font_01_sfnt_off0000f19c.bin
f6d48fe078837e5ff240024bea6cb0a24b33bfb77538a6ec4ce2ae2527c4b36e
pdf-font-stream PDF embedded font (sfnt) at offset 0xF19C 10836 bytes