Malicious PDF — malware analysis report

Static analysis result for SHA-256 811406f720d7b0f1…

MALICIOUS

PDF

81.4 KB Created: 2021-09-09 11:05:56 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: efde27fad0fd916cc3618be452e512fe SHA-1: 32de975450a051763f02e865b6893a698f30df92 SHA-256: 811406f720d7b0f10045b701d722375d5d1e9e8ee92384487a27be5bcf5f0a44
196 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous links to external websites, many of which are hosted on compromised CMS platforms or disposable domains, indicating a link farm designed to redirect users to malicious content. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or malware distribution. Although no scripts were explicitly extracted, the PDF structure and URL heuristics point towards an attack pattern involving redirection to potentially harmful sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9960

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://eugensa.lt/app/webroot/uploads/userfiles/files/zodav.pdf
    • https://retentionstudentexperience.com/wp-content/plugins/formcraft/file-upload/server/content/files/16134ccb8db72e---nuporigiboduwux.pdf
    • http://www.anglometais.com.br/adm/Editor/ckfinder/userfiles/files/jijivopedibife.pdf
    • https://wecareu.net/ckfinder/userfiles/files/90272588990.pdf
    • https://nichecnk.leaddeehub.com/userfiles/files/tipoza.pdf
    • http://go-trec.com/wp-content/plugins/super-forms/uploads/php/files/5hpnsao0mv3d1l3cp4j1qvkv9i/17889951563.pdf
    • https://salondumariagededijon.com/userfiles/file/43692264977.pdf
    • http://casaledellasignora.it/userfiles/files/bufelokemebawi.pdf
    • http://schokofontaene.de/idata/tuvixo.pdf
    • https://www.hungarianassociation.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613371ac7bae2---49209616134.pdf
    • https://wurstfargo.com/wp-content/plugins/super-forms/uploads/php/files/0be2c5d95805d28563bfa46a5fc7e15e/24583978257.pdf
    • http://mwcapital.net/ckfinder/userfiles/files/vedafexeposovenus.pdf
    • http://cofetariafraguta.ro/UserFiles/file/lexuzigi.pdf
    • http://kaplanpm.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613175e1d4f25---22727472957.pdf
    • http://businesslegalgroup.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/lejovoxoperiluvedabixuga.pdf
    • http://borisovhlebprom.by/var/upload/file/gojozuruda.pdf
    • https://simorgh.it/uploads/file/66354579443.pdf
    • https://yocarbroker.com/upload/ckfinder/files/89647863120.pdf
    • https://www.truesdalepainting.com/wp-content/plugins/formcraft/file-upload/server/content/files/161365f96524d1---32630697885.pdf
    • http://akkoryazilim.com/userfiles/file/zemexokizifapibonew.pdf
    • http://quanhoangtsi.com/upload/quangtri/files/99897424373.pdf
    • https://internationallanguagenavigators.com/media/vejamogifofogajanapif.pdf
    • https://www.aifimm.it/admin/inc/ckfinder/userfiles/files/zuwuzibumozidimopovabosex.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/cv9VXjIrmdE/uplcv?utm_term=5th+edition+dungeon+master%27s+guide+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_off0000d909.bin
6a4b1b4a15650ec8e627cd1de5a0715099752efe7656a164c4303786b81a5e57
pdf-font-stream PDF embedded font (sfnt) at offset 0xD909 17556 bytes
font_01_sfnt_off0001065c.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x1065C 16792 bytes
font_02_sfnt_off00011e73.bin
61f0a31aea874ac0e62d7cd8264de666211d7a0697b77766c21a58b16e87ef24
pdf-font-stream PDF embedded font (sfnt) at offset 0x11E73 11068 bytes