Malicious PDF — malware analysis report

Static analysis result for SHA-256 531662610d9f8433…

MALICIOUS

PDF

69.4 KB Created: 2021-09-13 03:47:40 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 4275b40bf2838d3e5c9bd810ca35fbca SHA-1: 2b406d7fe803c59a4a1c5733ddc2305dd64180d6 SHA-256: 531662610d9f8433a6d39a9bf62279c0f9acb28cfdce8ce1d954dd138214749e
156 Risk Score

Malware Insights

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

The PDF file was identified as malicious by ML classifiers and ClamAV, specifically flagged as a phishing trojan. Heuristics indicate it functions as a link farm, directing users to multiple external URLs, some hosted on compromised CMS uploads and disposable domains. The presence of numerous unknown URLs suggests an attempt to distribute or redirect users to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9965

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://tsnpharma.com/upload/files/jokuvexugopuwasetejoto.pdf In PDF document text
    • https://machnhaduong.com/images/uploads/files/82119543159.pdfIn PDF document text
    • https://gamedunyasi.com/calisma2/files/uploads/14259383972.pdfIn PDF document text
    • http://tydafa.com/dafa/uploadfiles/20210905185556.pdfIn PDF document text
    • https://www.hsbofmn.com/ckfinder/userfiles/files/5237326770.pdfIn PDF document text
    • https://aiaciran.org/cache/fck_files/file/zepufozidaduj.pdfIn PDF document text
    • https://worldmedglobal.com/userfiles/files/ludulisufimijanej.pdfIn PDF document text
    • http://pathtojanna.com/userfiles/files/9254047227.pdfIn PDF document text
    • https://ap-qatar.com/userfiles/files/senozozu.pdfIn PDF document text
    • https://ms2oke.com/contents/files/44895892042.pdfIn PDF document text
    • http://chingyi.tw/userfiles/files/tubizezosokoxafenoxijik.pdfIn PDF document text
    • http://lor-rostov.su/userfiles/files/91752214914.pdfIn PDF document text
    • https://stewsites.com/wp-content/plugins/super-forms/uploads/php/files/ea4ffce53f65efc4b1330973411ae1b9/xuraliratozeno.pdfIn PDF document text
    • http://infas.cz/images/wiswig/file/wagujur.pdfIn PDF document text
    • https://autohausnschmidt.de/userfiles/file/bezamenekisi.pdfIn PDF document text
    • https://gruntbudowa.pl/files/file/45280783324.pdfIn PDF document text
    • http://bowenlawmt.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/raregogisubat.pdfIn PDF document text
    • https://gianlucabruno.it/dati/upload/file/tinajisegazivopivo.pdfIn PDF document text
    • https://www.beadvised.co.uk/wp-content/plugins/super-forms/uploads/php/files/c4602abb8140e669cd277f21fb1e5055/99220428577.pdfIn PDF document text
    • http://familiehollander.nl/images/uploadedimages/file/42162330701.pdfIn PDF document text
    • http://cuanhomkinhtoanthang.com/media/file/ruwovumawitigunugufa.pdfIn PDF document text
    • https://amesmedicalservices.com/wp-content/plugins/formcraft/file-upload/server/content/files/161365c31134e1---64609142347.pdfIn PDF document text
    • http://maimungkorn.com/UserFiles/file/xunal.pdfIn PDF document text
    • http://sunnyten.net/userData/board/file/bupenemajuxopeborudu.pdfIn PDF document text
    • http://edwardfmcgintypa.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/31212181760.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/PmAiG5ZyT-k/uplcv?utm_term=ea+sports+ufc+3+download+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 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000b0ae.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB0AE 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000c8c0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC8C0 14948 bytes
SHA-256: 0555fb0fb7a3016deb0d13b0abd49f447674d0e173b5b820d98aa75863f74fde
font_02_sfnt_off0000eeab.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEEAB 10824 bytes
SHA-256: cc111e0377b96fdca031b9ed2b8c18aaa3c1d3d8c08b190875f36135d5f873c1