Malicious PDF — malware analysis report

Static analysis result for SHA-256 bc26e2742270b88f…

MALICIOUS

PDF

71.4 KB Created: 2021-09-22 11:07:25 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: 156458ff05c9c03aa1587338e2242d27 SHA-1: 788778de941e2e4c8b8a2c7445cda1d67c830cbf SHA-256: bc26e2742270b88f002cdd19049f11570c2e88a0b6e93e2a5a19c4cea0fe3281
156 Risk Score

Malware Insights

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

The file is identified as a malicious PDF by multiple heuristics and an ML classifier, with ClamAV detecting it as a phishing trojan. The PDF contains numerous embedded URLs, many of which point to external sites, including one hosted on a compromised WordPress upload directory. The document body is heavily obfuscated and appears to be generated by wkhtmltopdf, suggesting it's not intended for direct user reading but rather as a container for malicious links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

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://vodnik48.ru/content/file/80992727838.pdf In PDF document text
    • https://creteservices.com/FCKeditor/userimages/file/vinisenowepebosutusi.pdfIn PDF document text
    • http://wingmanresearch.com/userfiles/files/wabonofosifej.pdfIn PDF document text
    • http://veitali.com/upload/files/tidusawu.pdfIn PDF document text
    • http://www.risingstars.com.tr/wp-content/plugins/formcraft/file-upload/server/content/files/16146e2583fd70---dinoraboxenor.pdfIn PDF document text
    • http://nigerseedindia.com/uploads/79667343123.pdfIn PDF document text
    • https://gertiesbloomers.com/kousumi/nulook/upload/fckimages/file/tivogatabuxukasatuvupav.pdfIn PDF document text
    • https://projetovm.com/uploads/files/zojufasip.pdfIn PDF document text
    • https://matao.ro/app/webroot/files/userfiles/files/53798964422.pdfIn PDF document text
    • https://luatkhangthai.vn/upload/fck/file/6487297674.pdfIn PDF document text
    • http://mistral-paints.cz/userfiles/files/7089283815.pdfIn PDF document text
    • http://bordahusfeldolgozo.hu/editor_up/10042055350.pdfIn PDF document text
    • https://htapigroup3.com/contents/files/67299287423.pdfIn PDF document text
    • http://versobrokers.eu/userfiles/files/72570302034.pdfIn PDF document text
    • http://skulpt.in/admin/uploads/file/78768193594.pdfIn PDF document text
    • http://psychologyforeverybody.com/ckfinder/userfiles/files/67991056811.pdfIn PDF document text
    • https://advicezone.org.uk/wp-content/plugins/super-forms/uploads/php/files/adaredt4183nouljcvn7sv12nv/dimilusumurabaludemapol.pdfIn PDF document text
    • https://ilexgold.com/app/webroot/files/userfiles/files/xovujexa.pdfIn PDF document text
    • http://phutungvespaco.com/luutru/files/vileduzinotuvejudazes.pdfIn PDF document text
    • https://damiel.eu/userfiles/file/88764318460.pdfIn PDF document text
    • http://automotiveenergy.cz/userfiles/file/vojarunilokupu.pdfIn PDF document text
    • http://haozuowenwang.com/imagefiles/file/67455706164.pdfIn PDF document text
    • http://kaies.net/upfiles/file/1616492765.pdfIn PDF document text
    • https://www.d-table.com/wp-content/plugins/super-forms/uploads/php/files/0b49ed15053ea5692d7c7054bf648142/50234328981.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/FevRqgeaUVY/uplcv?utm_term=who+is+the+best+browser+for+androidPDF 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://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_off0000b66a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB66A 16116 bytes
SHA-256: 57c40c9040a95d7314098d62002c477b0efefc51ac6b4bfcdabadd61e82a77d9
font_01_sfnt_off0000df97.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDF97 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000f7ae.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF7AE 10624 bytes
SHA-256: 04d271d7465e1cc55c88c378de54e264735ee60edd9936762437baba1ddd123c