Malicious PDF — malware analysis report

Static analysis result for SHA-256 44c146a5e788e0ec…

MALICIOUS

PDF

83.1 KB Created: 2021-08-18 10:01:49 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: dff7d0d3b81df9aab45539543ac97b70 SHA-1: 92ae77d77675dc83e963da2cb5bea969f798546d SHA-256: 44c146a5e788e0ec2452d2713eb733e41fdd4f14f5fef0079ffa0b8e7740b15f
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many of which point to compromised WordPress sites or domains flagged as disposable link farms. The ML classifier and ClamAV detection strongly indicate malicious intent, likely phishing or malware distribution through these links. The document body is unreadable, but the heuristic firings and URL analysis are sufficient to determine the attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9990

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 https://xn--nmqu14inmf.com/upload/files/5015270756.pdf In PDF document text
    • https://blv.by/upload/editor/files/23673951629.pdfIn PDF document text
    • http://wittlich-luexem.de/userfiles/file/3494442164.pdfIn PDF document text
    • http://hasyo.net/files/file/93974849585.pdfIn PDF document text
    • http://altelaw.com/uploads/image/file/88031662435.pdfIn PDF document text
    • https://lisacutler.com/wp-content/plugins/formcraft/file-upload/server/content/files/16091cbd810867---bapakot.pdfIn PDF document text
    • http://springswellness.net/wp-content/plugins/formcraft/file-upload/server/content/files/1607d9da16cf32---rumufanifubudizezexalele.pdfIn PDF document text
    • https://www.alpha-dynamics.gr/wp-content/plugins/formcraft/file-upload/server/content/files/160b5423aaf233---13140003404.pdfIn PDF document text
    • http://www.lentilles-progressives.fr/wp-content/plugins/formcraft/file-upload/server/content/files/1607c6d7246367---gatuz.pdfIn PDF document text
    • https://autoschiller.de/wp-content/plugins/formcraft/file-upload/server/content/files/16114302fbd4d8---35494632182.pdfIn PDF document text
    • https://alteanetworks.fr/img/file/36941625582.pdfIn PDF document text
    • http://khacdautron.com/Images_upload/files/mufidoxuvuzabesi.pdfIn PDF document text
    • http://www.hypnotiseur.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a32421863f3---menilazawenarudixe.pdfIn PDF document text
    • http://ackerviewguesthouse.com/userfiles/file/4658875531.pdfIn PDF document text
    • http://aven.su/userfiles/file/sasafugavose.pdfIn PDF document text
    • https://edoxmarketing.com/wp-content/plugins/super-forms/uploads/php/files/n8scs5ok9e45hf8028p060inh1/notofotupuxireru.pdfIn PDF document text
    • http://wo-kop.pl/userfiles/file/70949803009.pdfIn PDF document text
    • http://gsoam.ge/wp-content/plugins/formcraft/file-upload/server/content/files/160e00886b167b---15968192732.pdfIn PDF document text
    • http://puntolinea.org/userfiles/files/3706129781.pdfIn PDF document text
    • http://ty-universe.com/image/files/20210612_113741.pdfIn PDF document text
    • http://wumag.pl/userfiles/file/37229791106.pdfIn PDF document text
    • http://joesservicecenternj.com/userfiles/files/lefiwiw.pdfIn PDF document text
    • http://controlsystemco.com/cache/fck_files/file/wojabadezemiw.pdfIn PDF document text
    • https://gionggiacam.com/ckfinder/userfiles/files/7261464829.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/ngfLrbzwjls/uplcv?utm_term=convexity+of+bond+formula+ca+finalPDF 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://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_off0000e270.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE270 11024 bytes
SHA-256: 33822be20e96eeb998851171f767c26a5305d8236d31b983bac8db77c800ebee
font_01_sfnt_off0000fc26.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFC26 17284 bytes
SHA-256: 4d9216654c3c894b6363d469f2771ced50b664dd11ba649747c61c6a9327b821
font_02_sfnt_off000129aa.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x129AA 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1