Malicious PDF — malware analysis report

Static analysis result for SHA-256 c616888a15dfce3c…

MALICIOUS

PDF

69.5 KB Created: 2021-09-25 09:11:02 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 57c5c128c8c0fd584194121a64f01b43 SHA-1: dd134793628d31bfc6485c5758dced3482efdcf4 SHA-256: c616888a15dfce3c9ad9d18f2559a551e909216c809c20139153ecf9cbf983cc
156 Risk Score

Malware Insights

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

The PDF file was flagged by ClamAV as Pdf.Phishing.Trojan and a machine learning classifier indicated a high probability of maliciousness. Heuristics identified the document as a link farm, with numerous URLs pointing to compromised websites or disposable hosting, likely intended to redirect users to malicious content. The presence of external URIs and link farms suggests an attempt to distribute phishing lures or malware.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9916

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://crysiq.ru/uplcv?utm_term=fortnite+app+for+phone
    • http://aloisiquadri.it/userfiles/files/10412105563.pdf
    • http://mabifitness.it/userfiles/files/mafupopiwa.pdf
    • http://daehnfeldt.com/userfiles/file/83848886017.pdf
    • http://daglichtfilters.nl/ckfinder/userfiles/files/vopezezevojadovosowudub.pdf
    • http://ingenermarket.ru/userfiles/52054718597.pdf
    • http://tomasmrazek.cz/userfiles/file/69311742050.pdf
    • http://hockjoohin.com/admin/uploads/file/7483087302.pdf
    • http://lauraestetica.com/userfiles/files/tadixowapuropedereki.pdf
    • https://hcs1000.org/wp-content/plugins/super-forms/uploads/php/files/531a0f6086c123951bd9dd0b3883f514/rafilijuvidek.pdf
    • http://tns-china.cn/editor_upload_image/file/4219638229.pdf
    • http://www.saraviation.com/wp-content/plugins/formcraft/file-upload/server/content/files/161370a720500d---60263898217.pdf
    • http://teewer.mn/ckfinder/userfiles/files/12812210993.pdf
    • http://culbertsonlawyer.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/pukerefa.pdf
    • http://pck.malopolska.pl/wp-content/plugins/super-forms/uploads/php/files/4dc2fb4712eb7068418ad6113aaa4363/xeluneba.pdf
    • http://hk-bbc.com/upload/file/81119913540.pdf
    • http://modernplating.com/userfiles/file/22881725596.pdf
    • http://www.driftime.ee/wp-content/plugins/formcraft/file-upload/server/content/files/16140e96fe4864---fopurejomuwojex.pdf
    • https://mediabandit.com/wp-content/plugins/formcraft/file-upload/server/content/files/161336cb4dca5e---78654730622.pdf
    • http://criollo-cocoa.com/userfiles/file/24914348001.pdf
    • http://gvs-russia.ru/admin/ckfinder/userfiles/files/42510804212.pdf
    • https://oilbasaro.com/web/images/ckfinder/files/20210918192239.pdf
    • https://limsurempat.com/contents/files/tudosegixutokapekafowu.pdf
    • http://gioiacompany.net/images/upload/file/daxitituzunowuxogi.pdf
    • https://www.fmworks.com.tr/wp-content/plugins/super-forms/uploads/php/files/8ql9jsn02d1qljur4jl2f5kbis/10083900202.pdf
    • http://bakefruit.com/uploads/files/202109050312573990.pdf
    • http://ebrinteractive.com/userfiles/file/5633328838.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_off0000b5ba.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xB5BA 16792 bytes
font_01_sfnt_off0000cdcc.bin
9e1e63996e5154454d4fec54747171f56911668391401b9df68ebc7dbffdca91
pdf-font-stream PDF embedded font (sfnt) at offset 0xCDCC 14264 bytes
font_02_sfnt_off0000f159.bin
dae3f1ec2a3ee1b4263bf35e54869d6d29d201a06feb2ffec42e875e89c2c84b
pdf-font-stream PDF embedded font (sfnt) at offset 0xF159 10216 bytes