Malicious PDF — malware analysis report

Static analysis result for SHA-256 f21a5a1179eef340…

MALICIOUS

PDF

77.9 KB Created: 2021-09-21 06:11:44 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 3eb901bf36aee67d38545c6e2d61c34b SHA-1: d1a4aaa3a5bf9b083db7ab7b47e69858b50af7fe SHA-256: f21a5a1179eef3404bb8c6e8c80b746467e6f9b31d36e40e8a04c6042371f754
196 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file contains numerous embedded links, many of which are hosted on compromised or disposable domains, suggesting a phishing or malware distribution attempt. The ClamAV detection and ML classifier strongly indicate malicious intent. While no scripts were explicitly extracted, the presence of external links and the nature of the heuristics point towards the document serving as a lure to download further malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9972

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 to algorithmically-generated URL high PDF_RANDOM_URL_LINK
    PDF contains a clickable HTTP(S) link whose host looks algorithmically generated (pronounceable-random labels) and whose path/query carries a long high-entropy token. This is the randomized-redirector pattern of malspam phishing lures — the visible document is only a prompt — not a PDF parser vulnerability.
  • 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://kaithompson.com/userfiles/file/20369725921.pdf
    • https://alismobile.co.uk/wp-content/plugins/super-forms/uploads/php/files/f2cb888371c0c40d7c834bfccdb52941/51456573196.pdf
    • http://avemkz.internet-match.com/upload/files/malukilojinosebaretuna.pdf
    • http://projecthouse.bg/uploads/CKfinder/files/wirunamofevibob.pdf
    • http://ambulatorioveterinariobubiniregini.eu/userfiles/files/82759900995.pdf
    • https://menu2uplus.com/images/file/kimikip.pdf
    • https://rakowka.pl/userfiles/file/pewezatodisi.pdf
    • https://wct.goldcrownresort.com/magazine_files/files/wosezenaw.pdf
    • http://mindentudor.hu/userfiles/file/fifesogadoridavupet.pdf
    • https://bikeid.net/ckfinder/userfiles/files/61565747708.pdf
    • https://pharmawell.eu/ckfinder/userfiles/files/3541577048.pdf
    • http://milwaukee.center/userfiles/file/xovixozevo.pdf
    • http://pilot-market.ru/new/files/file/32401254141.pdf
    • http://mikllc.mn/uploads/files/20213638805.pdf
    • https://ailani.org/wp-content/plugins/super-forms/uploads/php/files/6209c7e1bca3bf690c7fa48506ecaf82/948277883.pdf
    • https://slavica.ru/wp-content/plugins/super-forms/uploads/php/files/7e0bd35cbbe10ba15fdebeb6a6803eca/32846387941.pdf
    • https://lawyerupsmart.com/tempimg/file/94678629822.pdf
    • http://japanbizkorea.com/userData/ebizro_board/file/8443687331.pdf
    • http://broadgatecapital.com/userfiles/file/tejem.pdf
    • http://veganogle.es/uploads/ckfinder/files/82907170987.pdf
    • https://zd-zeta.com/uploads/files/202109012209221980.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/6naE_Nh8_CY/uplcv?utm_term=sky+tv+on+kodi+android
    • 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_off0000cf2f.bin
fe5ce960e22ff0837c2c90ec02d8808985e9e72c30aca31acc904c507cf51ff1
pdf-font-stream PDF embedded font (sfnt) at offset 0xCF2F 10240 bytes
font_01_sfnt_off0000e65b.bin
5962e0ee870c27feb6cf084e85dae2ef719b272ce5a9df63a170719baf073dbf
pdf-font-stream PDF embedded font (sfnt) at offset 0xE65B 17392 bytes
font_02_sfnt_off000112f8.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x112F8 16792 bytes