Malicious PDF — malware analysis report

Static analysis result for SHA-256 1374e75749169792…

MALICIOUS

PDF

91.3 KB Created: 2021-09-09 10:50:17 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: 80eaa9d96e46c7081a8ab0aea1da3186 SHA-1: 0e35d19db7434c7b5aefc6a2f0144465e12ceea6 SHA-256: 1374e75749169792a4427b507b1f0c03ff2e9798abc6d5ea10bc67163277fe9a
126 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. The PDF contains numerous links to external PDFs hosted on various domains, with one heuristic specifically flagging it as a link farm on disposable hosting. While no scripts were explicitly extracted, the presence of embedded URLs and the nature of the heuristics suggest a phishing or malware distribution attempt, likely initiated via spearphishing.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9929

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://clinivetmadonnadirosa.eu/userfiles/files/zukegabugelib.pdf In PDF document text
    • http://teamwork-poetschke.com/ckfinder/userfiles/files/4908778192.pdfIn PDF document text
    • https://bccphil.paramedix.biz/uploadfiles/file/gajif.pdfIn PDF document text
    • http://cartopack.be/Images/file/49714779153.pdfIn PDF document text
    • http://sswjeans.com/files/55125736858.pdfIn PDF document text
    • https://artedelvalle.cl/gal/files/file/wejij.pdfIn PDF document text
    • https://atlaskvartir.ua/data/uploads/files/10264945188.pdfIn PDF document text
    • http://aviteksural.ru/admin/ckfinder/userfiles/files/70385575622.pdfIn PDF document text
    • https://deltaguvenlik.net/userfiles/file/bowusexatowovamibo.pdfIn PDF document text
    • http://netichikawaya.com/userfiles/file/13548008616.pdfIn PDF document text
    • http://dialogueinpraxis.net/files/docs/loxagakamemi.pdfIn PDF document text
    • https://proxkimya.com/resimler/files/takadirolagudurolake.pdfIn PDF document text
    • http://speakingaboutnetworking.com/ckfinder/userfiles/files/67576543856.pdfIn PDF document text
    • http://wingmanplanningdemo.com/userfiles/files/xukidosuri.pdfIn PDF document text
    • https://thefertilizerproductionline.com/d/files/gotiwapubovu.pdfIn PDF document text
    • http://sxhk365.com/uploads/file///pibamofuvo.pdfIn PDF document text
    • http://villahetzwartepaard.nl/survey/userfiles/files/buneda.pdfIn PDF document text
    • http://greenhere.cn/upload/ckimg/files/202109091257029920.pdfIn PDF document text
    • https://tannhatviet.vn/upload/files/1754261505.pdfIn PDF document text
    • http://wabasnb.com/files/fckeditor/file/160058485861331689cca42.pdfIn PDF document text
    • https://szabobuszrendeles.hu/files/files/kevufepavazozimede.pdfIn PDF document text
    • http://gizmakina.com/depo/sayfaresim/file/mowovaxulipizo.pdfIn PDF document text
    • http://xn--ob0bjxt9h99icicrvkksa421cwwp7hiv4d6a.com/ckfinder/userfiles/files/mezegotududuvikunamavi.pdfIn PDF document text
    • http://xn--2-140-swe8h.xn--p1ai/files/45426703876.pdfIn PDF document text
    • http://orderbestwings.com/uploads/files/66883455972.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/GLLx1DTH0VQ/uplcv?utm_term=idioms+in+english+pdf+downloadPDF 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_off00010213.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10213 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00011a25.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11A25 17644 bytes
SHA-256: e626b4bf3ec9dacd00647a3bce6724067a00a8adee6efba2549da2e9a578ee99
font_02_sfnt_off0001479c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1479C 10784 bytes
SHA-256: 088db43ce334cb6ad47e65b2b8f65695b1c2a233d9f2c6b2416a0616f37137cb