Malicious PDF — malware analysis report

Static analysis result for SHA-256 1eff7383042b43c8…

MALICIOUS

PDF

87.0 KB Created: 2021-09-18 04:17:09 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 3a5540749146f05d3eb5d4c200e6e881 SHA-1: ae1a3c650fdb2fec3bcdcb0e453b59381e9481a9 SHA-256: 1eff7383042b43c8ded7a77f2f2b7ef42e38fab16a2c1c7df873a6f409ecca79
146 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF file flagged by ML classifiers and ClamAV as malicious. It contains numerous embedded URLs, many pointing to disposable domains, and exhibits characteristics of a link farm. The PDF structure is malformed, suggesting an attempt to exploit vulnerabilities or hide malicious content. While no scripts were explicitly extracted, the presence of malformed streams and external URIs indicates an attempt to redirect the user to malicious sites, likely for phishing or malware delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9976

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
  • 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.
  • 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://thehouseproduction.net/file/90942114171.pdf In PDF document text
    • http://uralinteh.com/uploads/files/7698000620.pdfIn PDF document text
    • https://feltshoe.com/userfiles/file/rijogivorumulufog.pdfIn PDF document text
    • http://bosch-elektronarzedzia.pl/catalog/file/94348193942.pdfIn PDF document text
    • http://www.asiacoservice.com/file/files/27530296012.pdfIn PDF document text
    • http://rexant.by/upload/editor/files/24787560016.pdfIn PDF document text
    • https://hongmao.tw/uploads/files/202109102154126772.pdfIn PDF document text
    • http://tantex.org/tantex/tantexuserfiles/file/vatodufepusenexib.pdfIn PDF document text
    • https://mytopics.it/uploads/file/44559105772.pdfIn PDF document text
    • http://ranch.pl/files/file/zudolaviniberoruzarufa.pdfIn PDF document text
    • http://unseretochter.ch/images/file/81223948861.pdfIn PDF document text
    • http://gostium.com/wp-content/plugins/formcraft/file-upload/server/content/files/161329fcb43091---bitofirevisuwuzapaz.pdfIn PDF document text
    • http://newgrids.com/userfiles/file/giturixidabiripegirogur.pdfIn PDF document text
    • http://templeton.sk/userfiles/file/58286843124.pdfIn PDF document text
    • http://ecohouse-lab.com/userfiles/file/92358164518.pdfIn PDF document text
    • https://oncallanatomist.com/ckfinder/userfiles/files/pesowujutapuwolupezo.pdfIn PDF document text
    • https://cobaltinc.org/userfiles/file/32929569301.pdfIn PDF document text
    • https://kme.pl/global/app/webroot/uploads/file/1630669808266.pdfIn PDF document text
    • http://iccjsc.vn/images/uploads/files/xegapa.pdfIn PDF document text
    • https://calprin.com/ckfinder/userfiles/files/luladeba.pdfIn PDF document text
    • http://afslab.asia/upload/files/94803408029.pdfIn PDF document text
    • http://veterinariomauracotti.it/userfiles/files/xufanixo.pdfIn PDF document text
    • http://free-note.kr/files/fckeditor/file/1784868189613e090189bdd.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/PmAiG5ZyT-k/uplcv?utm_term=call+recording+in+android+9PDF 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_off0000ee6e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEE6E 18560 bytes
SHA-256: 6f1c7bd2209563fa30609d98cbca633fa4c9a9310c4b9fb6bc79ce01d74be746
font_01_sfnt_off00011ea7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11EA7 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000136be.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x136BE 10480 bytes
SHA-256: 7b66621f719a7218f0dcc2873e4605568110e40d7241859f61a7ce55fa5e7e26