Malicious PDF — malware analysis report

Static analysis result for SHA-256 ef81b3ea085a881c…

MALICIOUS

PDF

84.7 KB Created: 2021-09-22 12:15:08 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 7020fe946e22ec48818c831771d8d8f8 SHA-1: ae2155f8cc8bb79ccb6e438620d96908a609b074 SHA-256: ef81b3ea085a881c6dc90a23ea9d79e7bf6b89360b47f5aa50e91c8659327d2e
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF was flagged by multiple heuristics and a machine learning classifier as malicious, with ClamAV identifying it as a phishing trojan. The PDF contains numerous external links, many pointing to disposable domains, suggesting a link farm or redirection mechanism to malicious sites. While no scripts were explicitly extracted, the PDF structure and heuristic firings indicate it's designed to redirect users, likely as part of a phishing or malware distribution campaign.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9956

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://shastriratanchatterjee.com/ckfinder/userfiles/files/16857551957.pdf In PDF document text
    • https://alwaysthesame.pt/site/upload/file/45894797285.pdfIn PDF document text
    • https://nidi.mk/ckfinder/userfiles/files/53933092403.pdfIn PDF document text
    • http://sxnqx.org/upload/file/Fl202109091925186680.pdfIn PDF document text
    • http://sirindhorn.net/upload/File/70221747666.pdfIn PDF document text
    • https://bushregenerators.biz/userfiles/files/26678854955.pdfIn PDF document text
    • http://bretagne.annuaire-regional.com/ckfinder/userfiles/files/98932987599.pdfIn PDF document text
    • http://shiokuda1.com/contents/files/15366272441.pdfIn PDF document text
    • http://physocare.com/Images_upload/files/28120629782.pdfIn PDF document text
    • https://swaarm.de/app/webroot/upload/files/rinusimatovokanexoga.pdfIn PDF document text
    • http://munnarinfo.in/userfiles/file/62905272214.pdfIn PDF document text
    • https://mintowncoffee.net/uploads/images/files/lefugojetukikemipubamej.pdfIn PDF document text
    • http://itnetworkconsultingsf.com/helpdesk/app/webroot/img/userfiles/files/mivixonatifef.pdfIn PDF document text
    • http://rulada.by/upload/editor/files/perurev.pdfIn PDF document text
    • http://ecompletecontact.com/ckfinder/userfiles/files/texowatawajaxikipupu.pdfIn PDF document text
    • http://7profi.net/userfiles/file/genonuzude.pdfIn PDF document text
    • https://unicon-msk.ru/data/files/bifoxanezerenonasivareva.pdfIn PDF document text
    • http://supair-lux.hu/ckfinder/userfiles/files/36963824846.pdfIn PDF document text
    • http://www.binghan.my/userfiles/file/donoxuzaxoveve.pdfIn PDF document text
    • http://gyogytornasz.hu/editor_up/bopokodarokexaketeka.pdfIn PDF document text
    • http://randygordonlawoffice.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/90930994361.pdfIn PDF document text
    • http://studiopassarotti.it/userfiles/files/41267601623.pdfIn PDF document text
    • https://salwangurugram.com/files/23451005.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/3vuEKuznOb8/uplcv?utm_term=sulthan+tamil+movie+online+playPDF 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_off0000e653.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE653 17872 bytes
SHA-256: 0312eb13f9229870f3abf3d9dc9747dde915bb703fb8809f5c14f7c1f514a20d
font_01_sfnt_off0001153a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1153A 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00012d51.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12D51 10604 bytes
SHA-256: 4e36973c123420bf0ba210b5a080ca8f82ab4d4efab50e5ecc9b940d61d86f7b