Malicious PDF — malware analysis report

Static analysis result for SHA-256 166caaf5745648cb…

MALICIOUS

PDF

86.7 KB Created: 2021-04-10 03:01:21 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-05-26
MD5: de02267cb39568554f680c45501ac16c SHA-1: e787b322b647ef7cf7927e24a6cbc108a8c25ed4 SHA-256: 166caaf5745648cb57b2a3201d6f752e2fe1fd3bd787c2a6c1de9602ff81df7f
126 Risk Score

Malware Insights

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

The sample is identified as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. The presence of numerous external URIs, many pointing to disposable or suspicious domains, suggests a link farm or phishing lure designed to redirect users to malicious content. Although no scripts were explicitly extracted, the PDF structure and heuristic firings strongly suggest it's designed to exploit vulnerabilities or trick users into downloading further payloads, aligning with common phishing and malware distribution techniques.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9996

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://grossenbacher.co.nz/en/system/files/avoidance-training-certificates/bekam.pdf In PDF document text
    • https://www.uts.cw/sites/default/files/webform/bofuwidesuxugebogaxa.pdfIn PDF document text
    • http://www.pacificsportfraservalley.com/sites/default/files/webform/zajufofagobixipisuna.pdfIn PDF document text
    • http://www.friendlycc.com/sites/default/files/webform/topevonizudurazot.pdfIn PDF document text
    • http://klm3fg.grhosting.cz/sites/default/files/webform/files/5308316073.pdfIn PDF document text
    • https://www.osgeurope.com/sites/osg-corporate.dev/files/webform/80982398497.pdfIn PDF document text
    • https://www.natsihwa.org.au/sites/default/files/webform/21073527915.pdfIn PDF document text
    • http://portal-mysigma.com/system/files/student-proof/41429692510.pdfIn PDF document text
    • http://oaklandchildcare.org/sites/default/files/webform/wafawujozovu.pdfIn PDF document text
    • http://www.friendlycc.com/sites/default/files/webform/85881129832.pdfIn PDF document text
    • https://www.uts.cw/sites/default/files/webform/xewaz.pdfIn PDF document text
    • http://portal-mysigma.com/system/files/student-proof/pifudolaloxafedotodela.pdfIn PDF document text
    • http://cicatsalud.com/html/sites/default/files/webform/dekif.pdfIn PDF document text
    • https://aboss.by/sites/default/files/webform/10891008032.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/1eyvgo/aqOO/~3/A3Ryygt5BCM/uplcv?utm_term=ap+biology+exam+review+guide+answer+keyPDF link annotation
    • https://community.princeton.edu/system/files/webform/22535495660.pdfIn PDF document text
    • 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://scripts.sil.org/OFLIn PDF document text
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000ef88.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEF88 5596 bytes
SHA-256: c5177dc72e51323243ffb24b5dbf33c8c66afc93a6c7c911d49089b282bd9685
font_01_sfnt_off00010284.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10284 12048 bytes
SHA-256: a78f2fb84a5a7abdfcce2bec47150558a45321da69f240e4e9c2f6e87cf32223
font_02_sfnt_off00012af4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12AF4 16036 bytes
SHA-256: 9559dd1bd908241551916101fda3d445a26f5c4b506a1423f23393456f9d5940
font_03_sfnt_off00013f5d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13F5D 4324 bytes
SHA-256: 9f355172d696dda274cac500966718f112ce76951f19577ac4888987ea6471b2