Malicious PDF — malware analysis report

Static analysis result for SHA-256 3ba53ddb91a4ef09…

MALICIOUS

PDF

87.2 KB Created: 2021-07-06 22:08:15 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 6fe38e028ed6e44fa602d07dfa03f915 SHA-1: f77e43003fc9b2ca9e23e5b03bbb9cde12e50d10 SHA-256: 3ba53ddb91a4ef09cf757fb83c293547941207a30154a74659fec26f074a8827
244 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF contains multiple heuristics indicating malicious intent, including random URLs, links to compromised CMS uploads, and a password-protected archive lure. The ML classifier and ClamAV detection strongly suggest this is a malicious PDF, likely a phishing or trojan delivery mechanism. The presence of a 'download button' lure and password instructions points to an attempt to trick the user into downloading and decrypting a secondary payload.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9961

Heuristics 9

  • 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.
  • Password-protected archive handoff high SE_PASSWORD_ARCHIVE_LURE
    Document gives password instructions for an archive or attachment — often used to keep payloads encrypted until after gateway scanning
  • 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.
  • Visual download / call-to-action button lure low SE_DOWNLOAD_BUTTON
    Document contains a call-to-action phrase ('Click here to download', 'Download Now', etc.) — low-signal unless other findings point to a malicious workflow
  • 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://penzionriverside.cz/files/file/49997332937.pdf
    • https://robotics-institute.com/wp-content/plugins/super-forms/uploads/php/files/sehgr91r2ps27cn628o8jhpk6f/vofipujaza.pdf
    • https://sip7.pl/autoinstalator/sip7.online/wp-content/plugins/super-forms/uploads/php/files/42699256bffbf4fc08173164b0dc8a0d/tivix.pdf
    • https://capital-tic.com/upload/ckfinder_temp/files/20210706064734.pdf
    • https://adbetelparaguay.com/wp-content/plugins/super-forms/uploads/php/files/9a1299bd944c2fde725351bc803cf3fe/legowogegizumuralunadiko.pdf
    • http://inimtrento.it/userfiles/files/zukewirogijanidatozuxa.pdf
    • https://inoxquochoang.com/app/webroot/files/images/pages/files/mivorenufunexuxerapix.pdf
    • https://alamansyria.com/userfiles/file/dasesopopotinatim.pdf
    • http://www.dadosefatos.net.br/wp-content/plugins/formcraft/file-upload/server/content/files/1609c0494be29c---23128650712.pdf
    • http://www.auditsi.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c950da490f6---pewipatufovivinosawajib.pdf
    • https://pabausa.org/wp-content/plugins/formcraft/file-upload/server/content/files/1606ea8f3d98fd---85880583256.pdf
    • https://vickers-electronics.co.uk/wp-content/plugins/super-forms/uploads/php/files/1d0753207f77c21645ee9ad0972c6907/kifadesazigub.pdf
    • https://sailstudy.in/ckfinder/userfiles/files/nifixopovuken.pdf
    • https://nobleanimalsanctuary.org/wp-content/plugins/super-forms/uploads/php/files/tmp/37188434816.pdf
    • https://lsp.od.ua/wp-content/plugins/super-forms/uploads/php/files/glr64brmqh2e8qqfjqjuj5p1s3/40821753673.pdf
    • http://developmentassociationofnagaland.org/nbloom/fckuploads/file/29422796402.pdf
    • https://churchosonline.com/wp-content/plugins/super-forms/uploads/php/files/4aed503f2ef55e6f9281eab213c724d4/67775802140.pdf
    • http://www.kissdocs.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/1608b842aaa643---81973878683.pdf
    • http://www.yourhealthyourchoice.org/wp-content/plugins/formcraft/file-upload/server/content/files/1606cb86011c88---radujurotujixikizemilorim.pdf
    • http://moon-villa123.com/CKEdit/upload/files/nofav.pdf
    • https://inchirieriavioane.ro/wp-content/plugins/formcraft/file-upload/server/content/files/16070b07eb9983---96947176197.pdf
    • https://qpshouse.com/upload/image/file/jagugurarilunijir.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/zMnd8XtcwSM/uplcv?utm_term=download+winrar+full+version+free+for+windows+10
    • 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_off0000f3cf.bin
3259f918c2e0efacdf0b42c1731b8e444642b2a001a02d774a8529d555aae6ba
pdf-font-stream PDF embedded font (sfnt) at offset 0xF3CF 10676 bytes
font_01_sfnt_off00010c76.bin
09cf33b0675a461fc31aabba32b19c17ee016b09889b7ac5471741c25cc10264
pdf-font-stream PDF embedded font (sfnt) at offset 0x10C76 16728 bytes
font_02_sfnt_off00013763.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x13763 16792 bytes