Malicious PDF — malware analysis report

Static analysis result for SHA-256 43bd0cacc2ddada9…

MALICIOUS

PDF

82.7 KB Created: 2021-09-17 03:54:08 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: f685f78d31a2f990d93018cc5a39a4bd SHA-1: 096f0bf0642be5e32243f3e54f8c769a889b17e2 SHA-256: 43bd0cacc2ddada910e9ffca7b7feee68d0145422aa893ba426e549b64002d40
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was detected as malicious by ML classifiers and ClamAV, indicating a phishing or trojan threat. It contains numerous embedded URLs, many pointing to disposable domains, and one specifically mentions 'convert pdf to excel free app' in its UTM parameters, suggesting a lure. The PDF structure itself is also flagged for being a link farm on disposable hosting, reinforcing the phishing pretext.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9833

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://mahanakhon.pacedev.com/ckupload/files/39359894520.pdf In PDF document text
    • http://rootbeadmill.com/upload_fck/file/2021-9-4/20210904072805715263.pdfIn PDF document text
    • http://skncn.com/u/files/wovabamanakoxotujerul.pdfIn PDF document text
    • http://igigeothermal.jp/userfiles/file/pibopifogan.pdfIn PDF document text
    • https://economiadecomunion.net/ckfinder/userfiles/files/77006231620.pdfIn PDF document text
    • http://saraswatishikshamandir.com/singhania/downloads/file/95072318329.pdfIn PDF document text
    • https://mbzl-pro.xyz/web/img/podborky/files/pesowawuwinewirokolu.pdfIn PDF document text
    • http://beetsom.com/PROGRAM_FCKeditor_UserFiles/file/156756771613633d7e61d6.pdfIn PDF document text
    • http://mavelikaradiocese.org/rapha/ckfinder/userfiles/files/towenebagexore.pdfIn PDF document text
    • http://wxmx.cn/upload/ckimg/files/202109170658318103.pdfIn PDF document text
    • http://bakersfield.thepokeluau.com/uploads/files/93991110854.pdfIn PDF document text
    • http://f-okinawa.com/img/tmp/files/72076115104.pdfIn PDF document text
    • http://2m-m.eu/userfiles/files/zogepudanewofujalomeve.pdfIn PDF document text
    • http://language-coach.pl/uploads/files/xamiju.pdfIn PDF document text
    • http://maimungkorn.com/UserFiles/file/rukelajagafukovase.pdfIn PDF document text
    • http://kwik-it.ru/wp-content/plugins/formcraft/file-upload/server/content/files/16132bcaf0fb9a---gafogujilas.pdfIn PDF document text
    • http://scro.ru/pic/file/92168020282.pdfIn PDF document text
    • http://getsolarny.com/userfiles/file/vubumeva.pdfIn PDF document text
    • http://adams-gold.ru/archive/image/file/pitavepelup.pdfIn PDF document text
    • http://yanartekstil.com/firma/files/94025514844.pdfIn PDF document text
    • http://le-bouquet.be/userfiles/files/43547541363.pdfIn PDF document text
    • http://le-lemniscus-incandescent.fr/ckeditor/upload/files/divagufatavazixapovuxuna.pdfIn PDF document text
    • http://www.smartlandgroup.com/ckfinder/userfiles/files/kikakugus.pdfIn PDF document text
    • http://urdu-hadith.com/survey/userfiles/files/laposobutipiwojaza.pdfIn PDF document text
    • http://vegasoft.hr/wp-content/plugins/formcraft/file-upload/server/content/files/1613d0be510982---30003724036.pdfIn PDF document text
    • https://funcarele.com/ckfinder/userfiles/files/13246584548.pdfIn PDF document text
    • http://msnladyboy.com/ckfinder/userfiles/files/35359629147.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/fzgW7-mxBc0/uplcv?utm_term=convert+pdf+to+excel+free+appPDF 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_off0000dfb3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDFB3 10552 bytes
SHA-256: e9c223598df66a9f29cada7b58c6e52efa1c3a7445532f46b45fc57a7c4644ca
font_01_sfnt_off0000f7f6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF7F6 17792 bytes
SHA-256: 40d117f73678a38ba2aa64972d4769c2e95562b2ecb6056f1af16148e200a6ad
font_02_sfnt_off00012544.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12544 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1