Malicious PDF — malware analysis report

Static analysis result for SHA-256 b26c76477d3f0170…

MALICIOUS

PDF

124.3 KB Created: 2021-10-07 11:04:46 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-02
MD5: ff994ab92036c5d22f9ec2b116e7a90d SHA-1: 58b17799a4170c710e4235becfa8665ac6cb245c SHA-256: b26c76477d3f0170957eb7b2aa2b326f20ff09382a1f9f0a747ab182ffe8cdda
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. It contains numerous embedded URLs, many of which point to disposable domains, suggesting a link farm designed to redirect users to malicious content. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' indicates a deliberate attempt to obscure the final destination through multiple redirects.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9957

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://crysiq.ru/uplcv?utm_term=embryonic+stem+cell+research PDF link annotation
    • http://cuuhoatudong.com/upload/files/zedoxejifunebezevikerali.pdfIn PDF document text
    • https://artofsurfing.com/preview/ckfinder/userfiles/files/9823100412.pdfIn PDF document text
    • https://bistro-8.com/wp-content/plugins/super-forms/uploads/php/files/2aaedeb3a16afda90e4bde93fa11dd75/94094327487.pdfIn PDF document text
    • http://pho32shabu.com/uploads/files/84767570507.pdfIn PDF document text
    • https://himalayanthailand.com/image/upload/File/buzugokugomuxu.pdfIn PDF document text
    • http://dansungsala.com/uploads/files/tokuluxerax.pdfIn PDF document text
    • http://vasekurzy.cz/userfiles/file/79022454477.pdfIn PDF document text
    • http://autoscuolemontagna.it/userfiles/files/74606260778.pdfIn PDF document text
    • http://rlmlaw.com/images/edit_images/file/zetawisadataz.pdfIn PDF document text
    • https://atrax.hr/files/4400920321.pdfIn PDF document text
    • http://ubestsports.com/imager/files/20210927024545.pdfIn PDF document text
    • http://bpsstudio.hu/uploads/82636452897.pdfIn PDF document text
    • https://asfus.net/virgsurv/userfiles/file/27256920719.pdfIn PDF document text
    • http://saludocupacionalpso.com/home/wp-content/plugins/formcraft/file-upload/server/content/files/1615bcbff73efa---zanidaxuzidarexoladamexe.pdfIn PDF document text
    • http://khonggianmang.com/upload/files/tuxuzovugusiwitifexefikax.pdfIn PDF document text
    • https://unitjaya.com/contents/files/wodegiguvarub.pdfIn PDF document text
    • http://nenkin-t.com/upload_img/ck/files/94473020781.pdfIn PDF document text
    • http://csc0535.com/userfiles/file/20210921102657_7rsba1.pdfIn PDF document text
    • http://chupanhnoithat.vn/upload/files/mafiboko.pdfIn PDF document text
    • https://braus.uz/images/shared/file/76555016170.pdfIn PDF document text
    • http://yaqeen-eg.com/userfiles/file/2269317582.pdfIn PDF document text
    • http://vietnam-intraco.com/webroot/img/files/dotefaterejif.pdfIn PDF document text
    • http://lyzebrno.cz/userfiles/file/dakewiluzezulibakomile.pdfIn PDF document text
    • https://winpoasia.com/ckfinder/userfiles/files/bozudasumilegomorakupofu.pdfIn PDF document text
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#In PDF document text
    • http://purl.org/dc/elements/1.1/In PDF document text
    • http://ns.adobe.com/pdf/1.3/In PDF document text
    • http://ns.adobe.com/xap/1.0/In PDF document text
    • http://ns.adobe.com/xap/1.0/mm/In PDF document text
    • http://ns.adobe.com/xap/1.0/rights/In PDF document text
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00017bf6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x17BF6 21008 bytes
SHA-256: 597849990ccf0bc43c7215bafdc97bd9d06d5a7a50f73d83842d3150c0f69c40
font_01_sfnt_off0001b2d4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1B2D4 10732 bytes
SHA-256: 1f6a7c66b38d69b585bf74ea2ebf238fa33d1139e5913b297ff490506c7ddf68
font_02_sfnt_off0001cb4c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1CB4C 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1