Malicious PDF — malware analysis report

Static analysis result for SHA-256 ac74eac298e14629…

MALICIOUS

PDF

74.9 KB Created: 2021-09-28 16:06:01 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: fb445916ca8ee6f1e8f92d6e5ca49187 SHA-1: a6e12637a50cb280d177078bfb8ec4994846159a SHA-256: ac74eac298e14629e046797651901fbf129887772f97c4f177d79ef8a55e2c4a
126 Risk Score

Malware Insights

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

The sample was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It contains numerous embedded URLs pointing to various domains, suggesting a phishing or link-farming operation. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' specifically flags the PDF as a link farm on disposable hosting, reinforcing the phishing lure interpretation.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9976

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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 https://synerhu.ru/uplcv?utm_term=android+developer+notification PDF link annotation
    • https://prawobrzeze.info/userfiles/file/tesafa.pdfIn PDF document text
    • https://eastmanllc.net/ckfinder/userfiles/files/warelazu.pdfIn PDF document text
    • http://recviem.ru/img/upload/60572097558.pdfIn PDF document text
    • http://ljjxmining.com/uploadfile/file///2021092812192880.pdfIn PDF document text
    • https://suprastoc.ro/userfiles/file/dasutepuwimoveji.pdfIn PDF document text
    • http://minerva-collection.net/files/files/64451798217.pdfIn PDF document text
    • http://lanaecoloridabruzzo.it/userfiles/file/tezogorir.pdfIn PDF document text
    • http://boxerdapolenta.com/cmsimple/images/file/77009340835.pdfIn PDF document text
    • http://vivaldiskibus.com/FileData/ckfinder/files/20210901_5CC724D23EE7F93A.pdfIn PDF document text
    • http://ergo-logo-bamberg.de/userfiles/file/73176618015.pdfIn PDF document text
    • https://roarmysecurity.ro/mm/file/mopom.pdfIn PDF document text
    • http://tgroupsrl.com/userfiles/files/57037502326.pdfIn PDF document text
    • http://antansconstructions.com/ckfinder/userfiles/files/5026215854.pdfIn PDF document text
    • http://autosoftware.company/autoresponders_images/files/vepuzibevafafonobelomadi.pdfIn PDF document text
    • http://paroissedementon.fr/upload/files/28905841940.pdfIn PDF document text
    • https://aannemingsbedrijfbarthulsbosch.nl/userfiles/file/zokarigixovaxesakix.pdfIn PDF document text
    • https://eastmangroupllc.net/ckfinder/userfiles/files/kexofepitiji.pdfIn PDF document text
    • https://bankubezpieczen.pl/userfiles/file/xogufijoturevarijikas.pdfIn PDF document text
    • https://greenline.bg/userfiles/file/31301595750.pdfIn PDF document text
    • http://kuryakyn.ru/userfiles/file/57609687261.pdfIn PDF document text
    • https://cottingham-group.com/cufiles/files/13634360281.pdfIn PDF document text
    • https://bold-iot.com/uploads/files/202109231942423242.pdfIn PDF document text
    • http://gospelpour100voix.com/fichiers/newsletter/file/55285639317.pdfIn PDF document text
    • 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_off0000bfcc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBFCC 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000d7e3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD7E3 10492 bytes
SHA-256: 0b7bfce543695752c25cb95de0ec874deba49158c62c7a2d455126486d31a97c
font_02_sfnt_off0000efd8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEFD8 17780 bytes
SHA-256: 98e0d94a293bb3bc399e0a9ca1a537a43c96838e68673656202521b7d5e63923