Malicious PDF — malware analysis report

Static analysis result for SHA-256 f81e761ea3ff6282…

MALICIOUS

PDF

75.2 KB Created: 2021-09-10 20:28:11 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: f8952634e24425b1e1cf6419ffb2af3b SHA-1: 34d40fea53b6ba17b469d612d5d93260cf8cb4db SHA-256: f81e761ea3ff6282294867406b2f6f43931e56f32dd3938d81884cf7f23e7e2e
156 Risk Score

Malware Insights

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

This 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 hosting or compromised CMS uploads, indicating a link farm designed to redirect users to malicious content. The primary attack pattern involves luring users through these links, likely for credential harvesting or further malware delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9963

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 http://citadelcaralarms.com/userfiles/file/10777699501.pdf In PDF document text
    • https://anpheatingandac.com/nbloom/fckuploads/file/90416356297.pdfIn PDF document text
    • http://hosteleriayvending.com/ckfinder/userfiles/files/divudexesu.pdfIn PDF document text
    • http://xn--12cf1djdb6cbcafdbu1f1cudgcc8am4wf7htgd9de.com/ckfinder/images/files/fubupuduzexujunufalesuza.pdfIn PDF document text
    • http://studiopetrilli.it/userfiles/files/23108703022.pdfIn PDF document text
    • http://allier.proximeo.com/ckfinder/userfiles/files/ruworixukajomikusupilodu.pdfIn PDF document text
    • https://nitdgp.ac.in/uploads/userfiles/files/zuwabimugit.pdfIn PDF document text
    • http://skkouty.cz/ckfinder/userfiles/files/sulixokewexagubivewagogiv.pdfIn PDF document text
    • http://writtenmail.com/upload_images/file/vopin.pdfIn PDF document text
    • https://cananalimdar.com/wp-content/plugins/super-forms/uploads/php/files/283eo67q1sr0nga54drqa5htr9/lugigofa.pdfIn PDF document text
    • https://karlholmbygg.se/UserFiles/files/27964751373.pdfIn PDF document text
    • http://www.skupp.pl/wp-content/plugins/formcraft/file-upload/server/content/files/16133b80f64819---77379998258.pdfIn PDF document text
    • http://www.dawnrotaryclub.tw/UserFiles/files/73549188971.pdfIn PDF document text
    • https://thediamangroup.com/_images/files/97417495078.pdfIn PDF document text
    • http://fzcce.com/aimgs/uload/files/forojixesewazuxara.pdfIn PDF document text
    • http://rund.cz/UserFiles/File/11450935653.pdfIn PDF document text
    • https://www.birdandwildlifeteam.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613a327c10f44---70761197628.pdfIn PDF document text
    • https://tadimtursu.com/image/files/zuwusa.pdfIn PDF document text
    • https://www.budgetskemaet.dk/wp-content/plugins/formcraft/file-upload/server/content/files/16132aa1cf1c1d---mipalipufalol.pdfIn PDF document text
    • http://swaving-stalinrichting.nl/ckfinder/userfiles/files/gudoluxijiturugiz.pdfIn PDF document text
    • http://seamcc.com/UserFiles/files/tivivadanizazoguje.pdfIn PDF document text
    • http://aaaexpressheating.com/userfiles/file/61736147968.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/1KS0DP0cxss/uplcv?utm_term=tubemate+apk+for+iosPDF link annotation
    • 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_off0000c358.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC358 17144 bytes
SHA-256: d49316cea492bade1a6ca67d4280da999b273c9aa22501fe7ec16ed03a38114d
font_01_sfnt_off0000ef1a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEF1A 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00010731.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10731 10664 bytes
SHA-256: a7aa82faf0d3ff29e3e3b0862114fbd2539231b4448e80474f40ca107491e5f9