Malicious PDF — malware analysis report

Static analysis result for SHA-256 84debf53b4073688…

MALICIOUS

PDF

87.8 KB Created: 2021-09-23 14:42:11 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: c7f88f206e05ca2c12a3155ec210f598 SHA-1: a8255cbd34106f61d386013a150a3f7916c03d09 SHA-256: 84debf53b40736881dc7c549f57e2c64deefa97a86fbf3f03c17fb74834c0790
146 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. Heuristics indicate malformed streams and a link farm structure, suggesting it's designed to redirect users to potentially harmful external sites. Although no scripts were explicitly extracted, the PDF structure and embedded URLs point towards a phishing or malware distribution scheme, likely initiated via spearphishing.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9946

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 http://termosystem.pl/userfiles/file/segujofafug.pdf In PDF document text
    • http://protetyka-lublin.com/images/wyswig_images/file/xifiketonorokokexapul.pdfIn PDF document text
    • http://kadh.kr/bobod/upload/file/8736925325.pdfIn PDF document text
    • http://orvositudasbazis.eu/images/upload/file/51275414020.pdfIn PDF document text
    • http://cdn.eagle.mn/uploads/userfiles/files/87479839544.pdfIn PDF document text
    • https://www.mercedesbenzofaustinservice.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614976e6ca92c---sezugodopuleforixebex.pdfIn PDF document text
    • http://vxclouds.com/userfiles/file/pubepagosetudejegegamibe.pdfIn PDF document text
    • https://magnanerie-cazilhac.com/userfiles/file/nafitox.pdfIn PDF document text
    • https://posh.hr/files/37927473333.pdfIn PDF document text
    • http://villkasz.hu/editor_up/fozubonefipevaruxivo.pdfIn PDF document text
    • http://hpworld.hu/data/pic/Image/file/60484403667.pdfIn PDF document text
    • https://www.adcgrain.com/wp-content/plugins/super-forms/uploads/php/files/1451519031f0d0949aaaff8a57f3d8d3/lejenagamuloraxizut.pdfIn PDF document text
    • https://cnn-logistics.com/asset/files/fivune.pdfIn PDF document text
    • http://seoulgreeter.com/userData/board/file/naxol.pdfIn PDF document text
    • https://brawlcall.com/ckfinder/userfiles/files/tevufeforojolim.pdfIn PDF document text
    • http://vinhhangvien.com/upload/files/20706777490.pdfIn PDF document text
    • http://almawred-sy.com/files/adminfiles/files/tubedifovimetivut.pdfIn PDF document text
    • http://csc0516.com/userfiles/file/20210906233429_tgs52s.pdfIn PDF document text
    • https://combrooncom.com/contents/files/17161686040.pdfIn PDF document text
    • http://volareinmongolfiera.it/userfiles/files/memibudagufomudemifun.pdfIn PDF document text
    • http://abbuffalowings.com/uploads/files/45137749014.pdfIn PDF document text
    • http://prunay-en-yvelines.fr/ckfinder/userfiles/files/20095051196.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/zMnd8XtcwSM/uplcv?utm_term=best+security+lock+apps+for+androidPDF 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 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000d4f3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD4F3 10972 bytes
SHA-256: 79c3ed637f66ff884b8ed6f4632362848e630d6f303b647c6176f5db86e55794
font_01_sfnt_off0000ee9e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEE9E 17364 bytes
SHA-256: a4c6d93a770e3311f015530763cb7915ca9034297358b6d3a4f5b646131eeab4
font_02_sfnt_off00011b55.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11B55 18660 bytes
SHA-256: 5491c85adf327e9a4b994110783270bca7b8eae92bab9f2ec79cab09cd49f1be
font_03_sfnt_off00013988.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13988 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1