Malicious PDF — malware analysis report

Static analysis result for SHA-256 271a255fe38508a0…

MALICIOUS

PDF

93.4 KB Created: 2021-06-24 20:22:23 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-29
MD5: aee78aececce479260cb87e3fdcd04e5 SHA-1: da31a9eff8ce41c91136adf04545911bc5bbd898 SHA-256: 271a255fe38508a0a5d966e9b978c9e3cdfb0989897a0d653703b88cad542b1c
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The PDF contains a link farm pointing to multiple compromised websites, many of which host PDFs that appear to be disguised as application installers. The ML classifier and ClamAV detection strongly indicate malicious intent. The presence of embedded URLs and the nature of the heuristics suggest a phishing or malware distribution scheme.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9996

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://www.mysmilestudios.com/wp-content/plugins/super-forms/uploads/php/files/5b1f9230937e4e369f8bee8e697d92be/birujotozuj.pdf In PDF document text
    • http://loveperfectionschool.com/upload/file/gokawugagepanesur.pdfIn PDF document text
    • https://www.enterpriselighting.com/wp-content/plugins/super-forms/uploads/php/files/324e13c295bd666f56db717230eaea19/37738381183.pdfIn PDF document text
    • http://irinaburmistrova.ru/files/nudujid.pdfIn PDF document text
    • http://lawcab.ru/wp-content/plugins/formcraft/file-upload/server/content/files/1609104f85c183---xajonoxisixe.pdfIn PDF document text
    • http://katyababash.com/images/uploads/file/tiwukawo.pdfIn PDF document text
    • http://akbmodel.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a07d4d8f2e4---tenow.pdfIn PDF document text
    • https://nikoljski.com/ckfinder/userfiles/files/75335008375.pdfIn PDF document text
    • https://www.taxiserviceh24.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608f7373b7763---32010111386.pdfIn PDF document text
    • http://simonhoirup.dk/userfiles/file/3838153428.pdfIn PDF document text
    • https://cordovajewelry.com/images/file/74348748728.pdfIn PDF document text
    • https://www.modianodesign.com/wp-content/plugins/formcraft/file-upload/server/content/files/160977b7a2db04---37557334897.pdfIn PDF document text
    • https://graffitipaintstudio.com/wp-content/plugins/super-forms/uploads/php/files/1f614eee6aae254d1a39d34640fb72c7/zipabofubonobenujig.pdfIn PDF document text
    • https://alshaabcoop.com/userfiles/file/38800746376.pdfIn PDF document text
    • http://foire-fromages-et-vins.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608cda1aada8f---33515205958.pdfIn PDF document text
    • https://myphi.biz/nbloom/fckuploads/file/74884495139.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://www.daltonmaag.com/In PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/1xuhb7AK25c/uplcv?utm_term=sfvip+player+apk+downloadPDF 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
    • http://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
stream_004_off00012520.bin decompressed-pdf-stream PDF FlateDecoded stream at offset 0x12520 29432 bytes
SHA-256: 69a4b5b33fb136770707a60a9d710e222f1c32c0f2eec3d11ba4bd4ec5eef496
font_00_sfnt_off0000ee7d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEE7D 4984 bytes
SHA-256: 69800cd3042e3822fc4d7000eb8d71b012505935837476d6f9722f7cfaa54435
font_01_sfnt_off0000ff91.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFF91 10988 bytes
SHA-256: dac4a6690ad3a84fb3b405acd323df84217109fc7c635d35e73bf87f9d306430
font_03_sfnt_off00015887.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x15887 4324 bytes
SHA-256: 1062cd8ddf90f4344fa193b395386d5669df1a952e5759311ca261a71931f361