Malicious PDF — malware analysis report

Static analysis result for SHA-256 d8951e723fc8e04d…

MALICIOUS

PDF

69.6 KB Created: 2021-09-30 21:12:07 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 6503902574ab67ff8ac4273891738723 SHA-1: 1f26271021a711ff635eef9a9218a25894b74f92 SHA-256: d8951e723fc8e04ddad123cb4631bbc70ddbaa9cf72525fa393fe1afa15edafb
146 Risk Score

Malware Insights

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

The PDF file was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. It contains numerous embedded URLs, with a notable heuristic indicating a link farm on disposable hosting and one URL pointing directly to an IP address. The document body is heavily obfuscated, suggesting an attempt to hide its malicious intent, likely to redirect users to further malicious content or downloads.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9986

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://takipcisec.com/calisma2/files/uploads/60151122582.pdf In PDF document text
    • https://familienbilstrup.dk/ckfinder/userfiles/files/69363906915.pdfIn PDF document text
    • https://vroa.pl/chplusfiles/file/97963818447.pdfIn PDF document text
    • https://speculatio.in/ci/userfiles/files/14344771377.pdfIn PDF document text
    • http://hitplus.eu/userfiles/file/guzomizizitofidawopi.pdfIn PDF document text
    • https://spheresignal.com/app/webroot/userfiles/files/towibabexiwapor.pdfIn PDF document text
    • http://0048.pl/48files/file/86843056619.pdfIn PDF document text
    • https://nasikampung.info/contents/files/gititino.pdfIn PDF document text
    • http://79.170.40.182/boothtastic.com/wp-content/plugins/formcraft/file-upload/server/content/files/161559ea43765c---19717544471.pdfPDF link annotation
    • https://nuregio.de/wp-content/plugins/formcraft/file-upload/server/content/files/1615242cb5e498---zofaxiwedatezelanefidatu.pdfIn PDF document text
    • http://cappellastudio.it/userfiles/files/61502401284.pdfIn PDF document text
    • https://www.sacproblemleri.com/wp-content/plugins/formcraft/file-upload/server/content/files/161419f198c340---5155372568.pdfIn PDF document text
    • https://aimtronu.org/userfiles/file/99718249128.pdfIn PDF document text
    • https://bselink.com/userfiles/file/38351793032.pdfIn PDF document text
    • http://avanti-kuhni.ru/upload/files/77006594296.pdfIn PDF document text
    • https://buddhaart.in/userfiles/file/4372906519.pdfIn PDF document text
    • http://eko-baby.ru/userfiles/file/19253296891.pdfIn PDF document text
    • https://mysmartedu.com/uploadimages/files/57605395170.pdfIn PDF document text
    • http://margheritango.it/userfiles/file/namixisufago.pdfIn PDF document text
    • https://tradingphrases.com/userfiles/files/perodotulomevopalo.pdfIn PDF document text
    • http://spellenindex.nl/images/uploads/ridov.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/fzgW7-mxBc0/uplcv?utm_term=the+forest+2PDF 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_off0000b057.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB057 9988 bytes
SHA-256: 56c25b0007d7bb981a24cc5fa43b8d8df9495b652e1be16de4cf3875412e0786
font_01_sfnt_off0000c6b8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC6B8 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000deca.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDECA 16568 bytes
SHA-256: 654c5357d24967b7a45e85296167031ffa8fbde65f285fd3e49718042110c6fa