Malicious PDF — malware analysis report

Static analysis result for SHA-256 83e116ff0ff88604…

MALICIOUS

PDF

70.4 KB Created: 2021-10-01 16:59:21 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: aa8d2fa8d6fc1edef8f0d390b94451e3 SHA-1: 04d272c84ab7d5ee23dc8c9329ad60d9bd1f1cc5 SHA-256: 83e116ff0ff88604fac719a5ceea2a8c590e0a9149dd7a79d3ad5da61d5cc9ac
196 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous links to external websites, many hosted on compromised WordPress installations or disposable domains, indicating a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely phishing or malware distribution. Although no scripts were explicitly extracted, the PDF structure and URL patterns are consistent with techniques used to deliver second-stage payloads.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9982

Heuristics 7

  • 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 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 https://cructi.ru/uplcv?utm_term=fast+times+at+ridgemont+high+123movies
    • http://murzilka.biz/images/uploads/file/89651950236.pdf
    • http://baove24h.org/upload/files/turikonofanujefevumik.pdf
    • http://kondicionery-domodedovo.ru/upload_picture/file/3968902489.pdf
    • https://nk-sostanj.si/files/file/93431833096.pdf
    • http://autosoftware.company/autoresponders_images/files/kuxitamaxesakejexo.pdf
    • http://clairerolo.com/userfiles/file/95554858988.pdf
    • http://weighlessthisyear.com/ckfinder/userfiles/files/68329631254.pdf
    • https://gosselindesign.com/images/from_fckeditor/fichiers/kunusotededuwatozidelu.pdf
    • https://ashleymongolia.mn/uploads/files/91208287660.pdf
    • https://machnhaduong.com/images/uploads/files/5379263705.pdf
    • http://www.nuricomuvakfi.org/wp-content/plugins/super-forms/uploads/php/files/kedeoamcdbb35ttgt3rll263a0/sosibomusulofixobujer.pdf
    • https://cgeminfos.ma/upload/file/tebamugusuje.pdf
    • http://atya.eu/files/file/84394257995.pdf
    • https://peltonfell.org.uk/ckfinder/userfiles/files/25209720541.pdf
    • http://terapie-psi.ro/wp-content/plugins/formcraft/file-upload/server/content/files/16153a0c02cca9---vesipudaxokonajuj.pdf
    • http://fajni3333.fun4two.pl/uploads/assets/file/75177717079.pdf
    • https://www.audioclinica.pt/wp-content/plugins/super-forms/uploads/php/files/jbrnhus9lt3co38a995aq50qma/30371413169.pdf
    • http://telektrans.hu/editor_up/zejofenezoziserujimosa.pdf
    • https://ambulatorioveterinariosismondi.eu/file/tiwatun.pdf
    • https://alley.52886.tw/uploads/files/65154311849.pdf
    • http://taociren.com/upload/file/210929081716934376z25o2635ec88.pdf
    • http://sungwoneng.com/upfile_editor/2021/files/gesuzukakaguge.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_off0000b008.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xB008 16792 bytes
font_01_sfnt_off0000c81f.bin
869afb71f83113e68f6339074c18e1d299ed59a0652368c14249c7322b28c47d
pdf-font-stream PDF embedded font (sfnt) at offset 0xC81F 11036 bytes
font_02_sfnt_off0000e17f.bin
a52b6d5fb62846327cb7fc6cd103d747ee64296bf35e8295a5de3a5e025d83d5
pdf-font-stream PDF embedded font (sfnt) at offset 0xE17F 15768 bytes