Malicious PDF — malware analysis report

Static analysis result for SHA-256 9bff61fc1acd94c0…

MALICIOUS

PDF

81.8 KB Created: 2021-09-21 13:56:37 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 8d942b34dc492d51bdb826ecfe19accd SHA-1: bf5801a1b06980c1c357be30197878183019d07d SHA-256: 9bff61fc1acd94c0057f07bab57fe975f21d4830c7a0410b41b916c0510c68bd
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 appear to be part of a link farm designed for SEO manipulation. The ClamAV detection and ML classifier strongly indicate malicious intent, likely for phishing or distributing further malware. While no scripts were explicitly extracted, the nature of the links and the PDF structure suggest it's designed to redirect users to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9917

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://kristiankutschera.de/userfiles/file/fozabazifijizam.pdf
    • http://niengrangchuyensau.com/upload/contentFile/file/37460110334.pdf
    • http://socukorglutamatmentesfuszer.hu/ckfinder/userfiles/files/57280132879.pdf
    • http://www.airportlimofortlauderdale.net/wp-content/plugins/formcraft/file-upload/server/content/files/16141bae88716f---5141278162.pdf
    • https://bushregenerators.biz/userfiles/files/birobawub.pdf
    • https://eastmangroup.org/ckfinder/userfiles/files/suxaxuvemaziwopaku.pdf
    • http://studiotecnicomancini.eu/userfiles/files/dipunorurobuze.pdf
    • http://villalapinetafavignana.it/userfiles/files/32861243409.pdf
    • https://studioconcept-stand.com/fck_userfiles/file/xirinajid.pdf
    • https://psg66.ru/admin/ckfinder/userfiles/files/80689425605.pdf
    • http://progfin.pl/userfiles/file/vuwiwefozodedivugol.pdf
    • https://pluckywize.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613a95096d7df---17360886824.pdf
    • http://zs-oilfieldequip.ru/d/files/lugemowabej.pdf
    • http://ambulatorioveterinarioilghirlandaio.it/userfiles/files/88125900248.pdf
    • http://appli-veolia.net/ckfinder/userfiles/files/doluxadodubegojuruwapid.pdf
    • http://styrexon.cz/userfiles/file/29063541547.pdf
    • https://martensmgt.com/business_school/uploads/file/21037269597.pdf
    • http://ippinnudon.com/uploads/files/42941877479.pdf
    • https://ventadeterrenosurbanos.com/userfiles/file/sukibovetodunu.pdf
    • http://pansophers.com/wp-content/plugins/formcraft/file-upload/server/content/files/16142b4c1ee384---17599335889.pdf
    • https://artlabjo.com/userfiles/file/10473482506.pdf
    • http://opuspoint.com/ckfinder/userfiles/files/vojilixenilekolebuxeja.pdf
    • https://edenestates.com/ckfinder/userfiles/files/zosipurozajolisabuwe.pdf
    • http://www.rosabrockenhaus.ch/ckfinder/userfiles/files/27983282264.pdf
    • http://chapelguild.com/images/usr/resurovebinafevatoxoxob.pdf
    • http://jumpinfit.it/userfiles/files/xoseret.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/cv9VXjIrmdE/uplcv?utm_term=android+1+gta+v
    • 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_off0000dda9.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xDDA9 16792 bytes
font_01_sfnt_off0000f5bb.bin
6edb89754c6ec29de651cff568f50a6b20b53247f26f5616c5147c1458ae5f15
pdf-font-stream PDF embedded font (sfnt) at offset 0xF5BB 17388 bytes
font_02_sfnt_off000122b2.bin
3d567b2b709d4e1b803b459f0cf9f32746a7baedf1c42b2ade232c84c0d76db4
pdf-font-stream PDF embedded font (sfnt) at offset 0x122B2 10176 bytes