Malicious PDF — malware analysis report

Static analysis result for SHA-256 ef50120b81b077b6…

MALICIOUS

PDF

85.6 KB Created: 2021-09-21 05:42:57 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 04806b6db2a4eb99e76f1ca6ea2eb7c0 SHA-1: 4543d58f684482ca7e1b7b54f682acf2ad090de2 SHA-256: ef50120b81b077b675a3a00c5f21038195d9eb5714acd188b32193fdcf91128e
146 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF contains numerous external URIs, with one pointing to a raw IP address, suggesting a link farm designed to obscure the ultimate destination. The ML classifier strongly flagged this PDF as malicious, and ClamAV detected it as a phishing trojan. The presence of multiple PDF_URI heuristics and the ML score indicate a high likelihood of malicious intent, likely to lure users to a phishing site or download further malware.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9964

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
  • Clickable URI points to raw IP address medium PDF_URI_IP_LITERAL
    PDF contains a clickable HTTP(S) action whose host is a literal IPv4 address. Legitimate documents normally link to named domains; raw-IP destinations are common in disposable phishing and malware-delivery infrastructure.
  • 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://arch.ua/ckfinder/userfiles/files/dokobifewesolipafa.pdf In PDF document text
    • http://jadeite.ru/images/file/14143235214.pdfIn PDF document text
    • https://agribusiness.pk/wp-content/plugins/formcraft/file-upload/server/content/files/16145b31e234ce---99048401395.pdfIn PDF document text
    • http://hillsdalehorseboarding.com/ckfinder/userfiles/files/malavibesofavirawadigirub.pdfIn PDF document text
    • http://140.121.180.103/ckfinder/userfiles/files/79301617608.pdfPDF link annotation
    • http://around-sicily.net/userfiles/file/kabebametibemuf.pdfIn PDF document text
    • https://echipamente-scule.ro/userfiles/file/27157051367.pdfIn PDF document text
    • https://estidevelopers.com/wp-content/plugins/super-forms/uploads/php/files/7473eb51cf0f121541dcb04764f3fc2f/37628485318.pdfIn PDF document text
    • http://supair-lux.hu/ckfinder/userfiles/files/suzakexejusitobafis.pdfIn PDF document text
    • https://portalbime.com/UploadedFiles/New/file/59879734842.pdfIn PDF document text
    • http://orosweb.hu/userfiles/file/28319712881.pdfIn PDF document text
    • http://chelseafoodmart.com/uploads/files/33232014824.pdfIn PDF document text
    • http://dietgame.net/admin/fckeditor/data/file/20210903055756.pdfIn PDF document text
    • http://paddockj.com/user_data/editor/ckfinder/core/connector/php/upload/files/ravojozivananoxaviw.pdfIn PDF document text
    • http://kolaykanal.com/userfiles/files/77095031992.pdfIn PDF document text
    • http://avvocato-callegaro.it/public/file/40272051276.pdfIn PDF document text
    • https://cribpointonline.org/cribpointonline/userimages/file/woxarimutepiwovu.pdfIn PDF document text
    • http://inciboya.com/resimler/site/files/69868160395.pdfIn PDF document text
    • http://asiavent.com/UserFiles/file///80767565823.pdfIn PDF document text
    • http://splogservice.ru/content/files/tiwuxos.pdfIn PDF document text
    • http://a899.net/userfiles/file/fulapunibulixopazog.pdfIn PDF document text
    • http://ei-windykacja.pl/upload/file/ludaze.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/6naE_Nh8_CY/uplcv?utm_term=picasa+f%C3%BCr+android+tabletPDF 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_off0000e608.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE608 10800 bytes
SHA-256: 45dc3b63ebde40d4b9e35b9ef6474b44b65681c4ca59d25b9eb32067063d93f7
font_01_sfnt_off0000fef9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFEF9 19136 bytes
SHA-256: 750a5bf3b705218b05bceb7e5ac7a74afb7ae757fbfcbeeab93490aefd558388
font_02_sfnt_off00012f49.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12F49 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1