Malicious PDF — malware analysis report

Static analysis result for SHA-256 b2708c89d64116e1…

MALICIOUS

PDF

71.4 KB Created: 2021-09-25 22:03:57 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-23
MD5: 5018e81a7fcafebbba0d29f3cb85b763 SHA-1: 8b177ed2a293a80c758034e69fba0c3764ffccef SHA-256: b2708c89d64116e105f56289b3074d638876921f5692620740cbfc88a5673500
154 Risk Score

Malware Insights

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

The sample was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. The presence of embedded JavaScript and malformed stream lengths suggests an attempt to exploit PDF vulnerabilities. The numerous external URIs, including those in a link farm, point towards a phishing or malware distribution scheme.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

Heuristics 7

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • Malformed active-content stream length medium PDF_MALFORMED_EXPLOIT_STREAM_LENGTH
    A PDF stream that carries active/exploit-looking content has a declared /Length that does not match the recovered stream body. Malformed stream boundaries and length mismatches are common parser-evasion/supporting evidence around Reader exploit streams.
  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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 http://daisytalavera.com/userfiles/files/bolegikozezaliv.pdf In PDF document text
    • https://produse-zilan.ro/files/76381658653.pdfIn PDF document text
    • http://savalis.ru/userfiles/file/47553836799.pdfIn PDF document text
    • http://unitez.net/images/newtech/files/fozobavalulap.pdfIn PDF document text
    • http://dalnoboy.net/data/filestorage/upload/files/82541638954.pdfIn PDF document text
    • http://koszyczarek.pl/userfiles/file/26500800585.pdfIn PDF document text
    • http://dagmar-e.de/userfiles/file/kubalulimalatupeva.pdfIn PDF document text
    • http://innova-perila.ru/upload/files/97104423391.pdfIn PDF document text
    • http://objets.immoweiss.lu/userfiles/files/popifatosirekoxumur.pdfIn PDF document text
    • http://spartaksedlec.cz/spartaksedlec/userfiles/file/20622637488.pdfIn PDF document text
    • http://sghscsjamarai.org/guruhargobind/userfiles/file/37633623518.pdfIn PDF document text
    • http://ldksolar-officialliquidation.com/userfiles/files/54856804162.pdfIn PDF document text
    • https://nidi.mk/ckfinder/userfiles/files/dijinovifinogudupi.pdfIn PDF document text
    • http://newtrichur.com/userfiles/file/lovajisejinegadifati.pdfIn PDF document text
    • http://blow-w124.com/js/upload/files/91846077579.pdfIn PDF document text
    • http://sentezetutmerkezi.com/upload/ckfinder/files/59603829202.pdfIn PDF document text
    • http://demenagements-remond.fr/userfiles/file/20210925165518.pdfIn PDF document text
    • http://sccsfz.org/upload/2021-09/57812274295.pdfIn PDF document text
    • https://bizdrive.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1/1613ab89c02fd7---guzojitiruxawunime.pdfIn PDF document text
    • http://www.bongbansaigon.com/uploads/files/manawufujufabikogonuvij.pdfIn PDF document text
    • https://www.golaw.net/wp-content/plugins/formcraft/file-upload/server/content/files/1613b29780a9d8---jepunipasoxawomejejubi.pdfIn PDF document text
    • http://www.perlodrink.com/documents/24491437686.pdfIn PDF document text
    • https://cincia.ro/ckfinder/userfiles/files/ketajal.pdfIn PDF document text
    • https://sokolzgierz.pl/web/uploads/files/77182016244.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/fzgW7-mxBc0/uplcv?utm_term=isaimini+2021+hollywood+moviesPDF 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_off0000b26b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB26B 17568 bytes
SHA-256: 1c849898fa4c6360863112cd59976008f81330c6fd4f2a3db07654592d0af17c
font_01_sfnt_off0000df51.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDF51 10824 bytes
SHA-256: f193d94c8ef575ce7ba35574114e65bffc864418f5b54199c226dd065545dc15
font_02_sfnt_off0000f834.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF834 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1