Malicious PDF — malware analysis report

Static analysis result for SHA-256 331681020514db2b…

MALICIOUS

PDF

80.7 KB Created: 2021-09-17 11:58:32 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: b13cadf33d884c1967724f07b15c4135 SHA-1: 3c8933ed6bb3a55cb309616f5b85291824a64339 SHA-256: 331681020514db2b6ea0c0f9475a7cc6af7d3cb67b720756ac0462bd7ca1d1f2
156 Risk Score

Malware Insights

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

The PDF was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, directing users to multiple external URLs, some hosted on compromised CMS platforms. The document body is heavily obfuscated, preventing analysis of its specific content, but the presence of numerous links and the malware detection strongly suggest a phishing or malware distribution attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

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
  • PDF link farm points to compromised-WordPress upload storage medium PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM
    PDF contains multiple clickable links, across many distinct hosts, whose targets are random-slug files parked in the upload directories of vulnerable WordPress form plugins (FormCraft, Super Forms). This is the hallmark of the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains hosted on compromised sites. The PDF itself carries no exploit — the risk is the linked destinations.
  • 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://caycanh.vn/images/fck/file/fosesupinudu.pdf In PDF document text
    • https://ourlady-schools2.com/userfiles/files/peduxixijibiduxozuneg.pdfIn PDF document text
    • http://cloverdiamond.com/file/63975506521.pdfIn PDF document text
    • https://siyata.co.il/wp-content/plugins/formcraft/file-upload/server/content/files/1613c45818b8de---xufanesavivagifomunu.pdfIn PDF document text
    • http://www.impactit.in/ckfinder/userfiles/files/tobedi.pdfIn PDF document text
    • https://renteci.com/imagens/file/11144827863.pdfIn PDF document text
    • http://thecuriosityshot.com/vamepuxabupelumawu.pdfIn PDF document text
    • http://uniquecharacters.com/upload/files/27349098644.pdfIn PDF document text
    • http://myhomeinparis.com/userfiles/files/93552386323.pdfIn PDF document text
    • https://whitelightdesign.com/wp-content/plugins/super-forms/uploads/php/files/0adbbf2ce00f571c0225edfb337ba1a1/lumozebifelikivizu.pdfIn PDF document text
    • http://villalapinetafavignana.it/userfiles/files/89020146683.pdfIn PDF document text
    • https://adtw1.elfjane.com/ckfinder/userfiles/files/12294368187.pdfIn PDF document text
    • https://kaplaitalia.it/userfiles/files/88852824881.pdfIn PDF document text
    • http://srmtteaparty.com/uploads/files/202109021806319712.pdfIn PDF document text
    • https://drainscovers.com/wp-content/plugins/super-forms/uploads/php/files/bd5ecbc8ef4fbeaa046d88362de3fcdf/31720533179.pdfIn PDF document text
    • http://akicgiyim.com/userfiles/file/671361195.pdfIn PDF document text
    • http://metrominicabs.com/survey/userfiles/files/metazadefirupimolelajurul.pdfIn PDF document text
    • https://aimtronu.org/userfiles/file/50846420840.pdfIn PDF document text
    • http://standartbio.com/fckfiles/file/boxezopoxikipapa.pdfIn PDF document text
    • http://casaperugia.fr/userfiles/file/59538912605.pdfIn PDF document text
    • http://duythuc-bearing.vn/uploads/userfiles/file/xibapi.pdfIn PDF document text
    • http://taiwan-casters.com/userfiles/file/76238905016.pdfIn PDF document text
    • http://yjeverspeed.com/userfiles/file/viluxibedalopajexuno.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/fzgW7-mxBc0/uplcv?utm_term=lady+popular+mod+apk+unlimited+moneyPDF 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_off0000d5ba.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD5BA 10648 bytes
SHA-256: acc9ff4d2318c4550b20906fbbe415ec0d4b84d6735ed46992f305e7d5ecb046
font_01_sfnt_off0000ee06.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEE06 18088 bytes
SHA-256: f83433f309ede4d4f3b45a7bf41ba48a7d833395a2eba986bce3838fd471c6f4
font_02_sfnt_off00011cc9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11CC9 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1