Malicious PDF — malware analysis report

Static analysis result for SHA-256 cb0e824376d293e6…

MALICIOUS

PDF

81.8 KB Created: 2021-09-20 22:03:45 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 57f0a8d3c490796148d88f636ed3e3bc SHA-1: d2dfb4fa9f38f1be16523279b78733f1458a42cc SHA-256: cb0e824376d293e618db14f8bd10c8215f6b16710dbb5ba327862f8e58ddcc54
156 Risk Score

Malware Insights

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

The PDF contains numerous links, many pointing to disposable hosting or compromised CMS upload directories, indicating a link farm designed to redirect users. The ClamAV detection and ML classifier strongly suggest malicious intent, likely phishing or malware distribution. The presence of multiple external URIs and link farm heuristics supports this attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

Heuristics 6

  • 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 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://www.prshots.com/ckfinder/userfiles/files/sijovubixogukako.pdf
    • https://shih-tzu.ro/files/file/45948217800.pdf
    • https://ans5680.preneed91.com/upload/files/riseluz.pdf
    • http://wawabed.pl/uploads/userfiles/file/xazajuluxukitevix.pdf
    • https://ka-base.no/images_students/files/59567200149.pdf
    • http://appli-veolia.net/ckfinder/userfiles/files/87474087504.pdf
    • https://youkuvpn.com/upload/files/81842797695.pdf
    • https://nothingbutsafetyglasses.com/userfiles/file/94888636982.pdf
    • https://directprocessors.com/wp-content/plugins/formcraft/file-upload/server/content/files/16138f146cabb0---56139805444.pdf
    • https://www.yoursurveysurveyors.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/16145fb8c391d9---74382947137.pdf
    • https://guclupin.com/calisma2/files/uploads/jugevivikodetu.pdf
    • http://fitviewer.biz/files/file/13856794736.pdf
    • http://tuanayapim.com/rsm/files/18525187766.pdf
    • https://mujeresenmovimientoplus.com/userfiles/file/20353432016.pdf
    • http://ontheedgeofnow.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613904ce7af24---56435816456.pdf
    • http://fbrasil.com/userfiles/file///26060586694.pdf
    • http://leap-egypt.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613eb631009ef---78651000053.pdf
    • http://a-pluset.com/userfiles/51839756324.pdf
    • http://www.sloepverhuur-debiesbosch.nl/upload/files/lenapuxixemaxajezivuj.pdf
    • https://kakvkusno26.ru/wp-content/plugins/super-forms/uploads/php/files/8fd1b6a13a7ef36f833221708777ed91/kamitukikuwaloxiti.pdf
    • http://atut-biuro.com/uploaded/file/sakejuxapidomexevifajizek.pdf
    • http://studiotravenzolo.it/userfiles/files/pufedamigijopiti.pdf
    • http://boletos.luzservicos.com/ckfinder/userfiles/files/fuzipegapibofizuxezalu.pdf
    • http://keyflounge.nl/userfiles/file/romosetarur.pdf
    • http://robvancampen.nl/userfiles/file/55631177196.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/S30rS-6n6vg/uplcv?utm_term=voice+recorder+app+android
    • 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_off0000ddf2.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xDDF2 16792 bytes
font_01_sfnt_off0000f604.bin
9a1f813ef58da95e2b4ea670746963bb893871c7b1c3fc335497722aeb9e097d
pdf-font-stream PDF embedded font (sfnt) at offset 0xF604 17152 bytes
font_02_sfnt_off00012278.bin
f695e099dcd7fcb8934ce89bba0deb7477ba4dd3985793605e9607b65e2b95e6
pdf-font-stream PDF embedded font (sfnt) at offset 0x12278 10164 bytes