Malicious PDF — malware analysis report

Static analysis result for SHA-256 cd21ac9ca110105b…

MALICIOUS

PDF

82.9 KB Created: 2021-09-03 03:27:42 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 18a7832f3e42bb99bc955695623c9f2c SHA-1: f26f98cef0d00474846b67469ad54e8ffcd5c418 SHA-256: cd21ac9ca110105b7fd2cceafd9471fb2e5e36211ea7c5673f2394ac8d5211a7
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The file was detected as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. Heuristics reveal it functions as a link farm, directing users to multiple compromised WordPress sites. The presence of numerous external URIs, many hosted on potentially disposable domains, suggests a phishing or malware distribution campaign.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

Heuristics 6

  • 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 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://kindliving.org/wp-content/plugins/super-forms/uploads/php/files/tmp/60743844194.pdf
    • https://k9-warrior.com/wp-content/plugins/super-forms/uploads/php/files/smno5v4hkvl52l6mld4mngrmor/53065448037.pdf
    • https://akdenizokullari.k12.tr/wp-content/plugins/super-forms/uploads/php/files/dmejsvmasmuej9du252jdblmlq/roretifebavotidikig.pdf
    • https://houstoncoinshow.org/FCKeditor/file/misafapedoxawudibog.pdf
    • https://purpleleafestatebuyers.com/wp-content/plugins/formcraft/file-upload/server/content/files/160936be8355aa---29232375120.pdf
    • https://kisikana.hr/userfiles/file/60150118654.pdf
    • http://sten.kr/club/data/userfiles/file/20210808035209.pdf
    • http://antwerp-rentals.com/wp-content/plugins/formcraft/file-upload/server/content/files/1610d3e8613e3d---xisotabetupovonizeval.pdf
    • http://sevimticaret.net/userfiles/file/jifoduzejiwebev.pdf
    • https://majorsagilekvaros.hu/uploads/file/49271085951.pdf
    • https://www.cir.cloud/wp-content/plugins/formcraft/file-upload/server/content/files/160a5ea157bb02---kuzisakegigijekagazobazux.pdf
    • http://wccflooring.com/userfiles/files/65175783510.pdf
    • http://englandmatchshirts.com/assets/file/65305448354.pdf
    • http://xetaihyundai.net/upload/files/1174690914.pdf
    • http://thesecurityguardunion.ca/userfiles/files/reduwaxupeku.pdf
    • http://buergerforum-tirol.at/file/tazepamupejisavulozamifir.pdf
    • https://noblacklist.pro/web/img/podborky/files/98496365447.pdf
    • https://www.enviedecrire.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607f297006e8d---29931682281.pdf
    • https://www.advids.io/wp-content/plugins/formcraft/file-upload/server/content/files/160948ff83493a---vujitutovepipamasifupef.pdf
    • http://madmojo.com/fckupload/file/95240265723.pdf
    • http://scissortailfarms.com/wp-content/plugins/formcraft/file-upload/server/content/files/160731f9279499---vudefekilozu.pdf
    • https://www.assofmt.org/ckfinder/userfiles/files/27338375054.pdf
    • https://www.democratum.com/wp-content/plugins/super-forms/uploads/php/files/13e4b0f614c2a272d2751d4bb72711af/tolelimip.pdf
    • http://montpellier-businessplan.com/mbp/upload/images/images/upload/ckfinder/zazuxipa.pdf
    • https://www.winsum.frl/ckfinder/userfiles/files/sodibanopejugupimatimewug.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/YTWXjIUwRh0/uplcv?utm_term=varieties+of+english+language+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_off0000dd73.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xDD73 16792 bytes
font_01_sfnt_off0000f58a.bin
c715b302100ec8c16443767fe64f9b6d26c9986e556f01d3e808add5b16378bd
pdf-font-stream PDF embedded font (sfnt) at offset 0xF58A 10848 bytes
font_02_sfnt_off00010e45.bin
349c2c8decab52423dfc99392be9dbc0022382981d315a3926588dcd5be1b3ed
pdf-font-stream PDF embedded font (sfnt) at offset 0x10E45 18784 bytes