Malicious PDF — malware analysis report

Static analysis result for SHA-256 f8dd2cb2783ff7d0…

MALICIOUS

PDF

71.3 KB Created: 2021-09-29 09:21:59 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 0b1c9c58dfa2b3a1815bf367992e8ec3 SHA-1: 971fa83d48d7b901e104f76cb3f3e50c56cc682a SHA-256: f8dd2cb2783ff7d0e598e8505a1a1a93f7e56b37d7393f765041f5f2e2031d43
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many of which point to compromised CMS upload directories or disposable hosting, indicating a link farm designed to redirect users. The ClamAV detection and ML classifier strongly suggest malicious intent, likely phishing or malware delivery. The presence of multiple external URIs and link farm heuristics points towards an attempt to lure users to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9909

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://blnk.eu/userfiles/files/zuxudunofanopojibudasodaf.pdf
    • http://nutranghongngoc.com/media/ftp/file/80701838165.pdf
    • http://www.lbtfilm.com/uploads/files/voxivabumimukupuvikolava.pdf
    • https://bakwanudang.com/contents/files/72672719427.pdf
    • https://stpm-sa.com/userfiles/file/2043930680.pdf
    • https://g-ortho.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/16133bf21136ea---60918965078.pdf
    • http://www.mattig-accounting.bg/fisiere/file/zezipoxawekoxomelebuwex.pdf
    • http://bizbecho.com/pa/trainstation/uploads/image/file/babujajutuvujal.pdf
    • http://lignumweb.com/site/webroot/uploads/files/zewagizefusofepuwevisez.pdf
    • http://alwaysshine.com/fileimage/file/kiximewuxidifadar.pdf
    • http://re-media.ru/foto/ck/files/pemonemavaguwi.pdf
    • http://wpscrm.in/uploaded_files/userfiles/files/limunevidodegino.pdf
    • http://getem.eu/files/file/pakawanatunaveresupajok.pdf
    • http://vagtteam.com/userfiles/Files/tevuturudutatiwususuguzo.pdf
    • https://alkathirilaw.com/userfiles/files/97466458666.pdf
    • http://jinruily.com/UploadFile/file/20210926022653888.pdf
    • https://mimpiindah88.com/contents/files/93887389662.pdf
    • http://qianlong99.org/ckfinder/userfiles/files/67754816900.pdf
    • http://emanuelarombiarchitetto.eu/userfiles/files/tevesisapominesitepa.pdf
    • https://ubranni.com/uploader/files/razodosutuj.pdf
    • http://www.hptindia.com/wp-content/plugins/formcraft/file-upload/server/content/files/161336b546ae9f---36420027070.pdf
    • http://traviet36.com/upload/files/rutepefuzamopiseg.pdf
    • http://theponghop.com/upload/files/lapozuxovezegipeninomutad.pdf
    • http://jenan.com/ckfinder/userfiles/files/kuwizazineze.pdf
    • http://asalsold.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614731ee2065e---63899791078.pdf
    • http://xn--rssx31a7tec6p.com/upload/userfiles/files/20210901080914.pdf
    • http://noospc.ru/SITE/files/editor/file/88768459359.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/BkSY9tpko7c/uplcv?utm_term=advanced+vocabulary+exercises+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_off0000b615.bin
9a85e88ca75e50ba5cb583d47549878d604d17cda71dd0629186a3c8a677293f
pdf-font-stream PDF embedded font (sfnt) at offset 0xB615 11020 bytes
font_01_sfnt_off0000cfa7.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xCFA7 16792 bytes
font_02_sfnt_off0000e7b9.bin
112fd2e8787fcf789eaa8fb921c4bc09dac3ec44516b71c40933738a4323ecad
pdf-font-stream PDF embedded font (sfnt) at offset 0xE7B9 15580 bytes