Malicious PDF — malware analysis report

Static analysis result for SHA-256 b720ce99b33e89cb…

MALICIOUS

PDF

84.6 KB Created: 2021-09-23 04:31:29 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 53702159bd47fc46947171f0218acb6b SHA-1: 732256ab2bc9e9bbcf8cc4f6ed924821c4bce422 SHA-256: b720ce99b33e89cbfe121df3d67e8936fe6105a497728b202aea262c24aa8220
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF file contains a link farm pointing to multiple PDF documents hosted on compromised WordPress sites. These links are likely intended to lure users into downloading further malicious content, as indicated by the ClamAV detection and ML classifier flagging this file as a phishing trojan. The use of compromised CMS upload directories suggests an attempt to disguise the malicious infrastructure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9912

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://tnmkor.com/FileData/ckfinder/files/20210913_A461A19351A0C47D.pdf In PDF document text
    • https://aslimitada.com/userfiles/file/patojakawikatul.pdfIn PDF document text
    • https://amezdigital.com/wp-content/plugins/super-forms/uploads/php/files/2069f79c55dd3433a0e892a51a32bbe6/95363499816.pdfIn PDF document text
    • https://jecoexports.com/ckfinder/userfiles/files/8901791075.pdfIn PDF document text
    • http://hoangle.vn/uploads/userfiles/file/tosuru.pdfIn PDF document text
    • https://chicagoportablexray.com/wp-content/plugins/formcraft/file-upload/server/content/files/161351931d291b---58049402791.pdfIn PDF document text
    • https://swimproject.eu/wp-content/plugins/super-forms/uploads/php/files/a56cea02d4f5d763dbbec8f94bdb0d1a/87351988177.pdfIn PDF document text
    • https://jbdclothiers.net/emailer/userfiles/file/16188884333.pdfIn PDF document text
    • http://xn--82ca1bkibi6eufn5bh1b7i3e.com/UserFiles/File/99069638485.pdfIn PDF document text
    • http://www.siscbolivia.com/admin/uploaded/fck/file/56153246715.pdfIn PDF document text
    • https://8cj2aja7-8mxb.com/contents/files/larituguz.pdfIn PDF document text
    • https://chptravel.ir/data/file/betajusupiteferu.pdfIn PDF document text
    • http://www.enredmail.com/templates/files/idCliente_/file/jevifixirudifipofobum.pdfIn PDF document text
    • https://cahayaapi1.com/contents/files/65813961599.pdfIn PDF document text
    • http://isvpro.com/custom/files/22416985797.pdfIn PDF document text
    • http://ohadalegistrocbarter.com/ckeditor/uploads/files/dosugutiji.pdfIn PDF document text
    • https://karpataljaturizmus.hu/upload/tadutamovunudupulix.pdfIn PDF document text
    • http://www.tractortools.cz/ckfinder/userfiles/files/6007362295.pdfIn PDF document text
    • http://emiem.pl/public/upload/ckfinder/userfiles/files/wuvanomorezuj.pdfIn PDF document text
    • http://novo-foto.ru/ckfinder/userfiles/files/gugeboxotejabadukitewubaz.pdfIn PDF document text
    • https://miamiuniquelimo.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613d273ed6930---kodoro.pdfIn PDF document text
    • https://benhgout.net/uploads/Files/file/jozimogiponemifugewepux.pdfIn PDF document text
    • http://interwork.sk/userfiles/file/6760596175.pdfIn PDF document text
    • http://hijoin.hu/editor_up/lupazukinazo.pdfIn PDF document text
    • http://faceconnects.com/ci/userfiles/files/85371968324.pdfIn PDF document text
    • http://stimatacasa.eu/userfiles/files/tumegibevegama.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/A3Ryygt5BCM/uplcv?utm_term=how+to+stop+app+ads+on+android+phonePDF 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_off0000e786.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE786 10520 bytes
SHA-256: 51a6c80c18f78376915fe5e9ec656036889e0b6c0e8481168e053cf8123ba9b8
font_01_sfnt_off0000ff74.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFF74 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00011786.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11786 17204 bytes
SHA-256: e5964bd058a1cdea112c87c2dfae2e6223f87f71d8cd97aad492705f87f6cb51