Malicious PDF — malware analysis report

Static analysis result for SHA-256 bb988504749f3935…

MALICIOUS

PDF

84.7 KB Created: 2021-09-17 13:42:20 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: 2ec6a0ab2a29762f0a443b42fecb1eba SHA-1: 6b7202e6684131569b622f07b2720b80937b79fb SHA-256: bb988504749f393552a472ba274bb930f60146d83bb2a32d56e6cd3b864ecd9f
156 Risk Score

Malware Insights

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

The PDF contains a link farm with numerous external URIs, many pointing to compromised CMS upload directories. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or distributing further malware. The document body is heavily obfuscated and unreadable, providing no direct clues to its purpose beyond what the heuristics reveal.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

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
  • 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://d-a-s.cn/userfiles/file/75876907772.pdf In PDF document text
    • http://af.ssla.ru/images/fornews/files/24132678275.pdfIn PDF document text
    • https://realwebguys.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613ee1c168747---nupomu.pdfIn PDF document text
    • https://sunpower.lv/ckfinder/userfiles/files/ditukokumubibexitaloxebi.pdfIn PDF document text
    • https://mimpishio2bet.com/contents/files/vuwefavavegipon.pdfIn PDF document text
    • http://cukiernia-waltar.pl/qcms/userfiles/file/gaferadefedofotubone.pdfIn PDF document text
    • http://redeyeldn.com/userfiles/file/nufimezamakatakaniji.pdfIn PDF document text
    • http://remaining-mc.de/userfiles/file/natili.pdfIn PDF document text
    • https://conexkarvan.com/cache/fck_files/file/josikulena.pdfIn PDF document text
    • http://ingmontagna.com/userfiles/files/vafaxotorono.pdfIn PDF document text
    • https://wilocom.ro/ckfinder/userfiles/files/80824089967.pdfIn PDF document text
    • https://lecachet.fr/docs/files/siwebodejirakilemile.pdfIn PDF document text
    • https://fatheragneliti.com/wp-content/plugins/formcraft/file-upload/server/content/files/16141f0b9c76e8---tawona.pdfIn PDF document text
    • https://pmeds.us/userfiles/file/43175812101.pdfIn PDF document text
    • https://riolospettacoli.it/filesUploads/file/zelenuvurenudusox.pdfIn PDF document text
    • http://mail-ex.net/userfiles/file/64669519243.pdfIn PDF document text
    • http://sgyscom.com/upload_fck/file/2021-9-12/20210912210913994096.pdfIn PDF document text
    • https://echipamente-scule.ro/userfiles/file/89756417271.pdfIn PDF document text
    • http://autosvilar.com/uploads/ckfinder/files/63600928428.pdfIn PDF document text
    • http://www.barbazan-debat.fr/ckfinder/userfiles/files/96073170813.pdfIn PDF document text
    • http://laclonghotel.vn/upload/files/mebezozipanagusamililadag.pdfIn PDF document text
    • https://spherule.org/wp-content/plugins/super-forms/uploads/php/files/gk660oea5ilgc5i2jvsmacgcv0/48829848806.pdfIn PDF document text
    • http://nhac.ditimchanly.org/Images_upload/files/99265789803.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/FevRqgeaUVY/uplcv?utm_term=ludo+app+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_off0000e834.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE834 9996 bytes
SHA-256: a4214efcc307a9de07f00c5d7b47c0962ae3ef46d47b3e14a61a4ea8b8ffd678
font_01_sfnt_off0000fe57.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFE57 18056 bytes
SHA-256: d5c9d5ca15723c0f975be921b43d24b6922f78ee71235d5036e96bd197185af4
font_02_sfnt_off00012d3a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12D3A 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1