Malicious PDF — malware analysis report

Static analysis result for SHA-256 77b14655e873a9b8…

MALICIOUS

PDF

78.4 KB Created: 2021-07-02 11:26:50 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-08-20
MD5: b77051fcaf4dcffdc864b52e4e30fa54 SHA-1: 63d56184bf078d110a069638467d1ab536a1fbb8 SHA-256: 77b14655e873a9b8f6b327cfa1eda8e6f27d05fc35b1add02cfb5bef5c80c62a
176 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous links pointing to compromised websites, indicating a phishing or malware distribution attempt. The 'PDF_MALFORMED_EXPLOIT_STREAM_LENGTH' heuristic and ML classifier strongly suggest malicious intent. While no scripts were explicitly extracted, the presence of external URIs and the overall structure point towards a malicious document, likely delivered via spearphishing.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9950

Heuristics 7

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • Malformed active-content stream length medium PDF_MALFORMED_EXPLOIT_STREAM_LENGTH
    A PDF stream that carries active/exploit-looking content has a declared /Length that does not match the recovered stream body. Malformed stream boundaries and length mismatches are common parser-evasion/supporting evidence around Reader exploit streams.
  • 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://asiaviews.org/wp-content/plugins/super-forms/uploads/php/files/6uipi1p76so81e4a4mb7098qh1/sakezixa.pdf In PDF document text
    • http://goldway.jp/upload/board/file/67256451066.pdfIn PDF document text
    • https://sk-developers.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609db82b0f6b3---4912492163.pdfIn PDF document text
    • http://bfr-bialapodlaska.pl/userfiles/file/zibiposenibiketoge.pdfIn PDF document text
    • https://flycam.com.tr/wp-content/plugins/formcraft/file-upload/server/content/files/160a9138314b13---28232825473.pdfIn PDF document text
    • http://nhaphangmy.us/upload/files/24428167532.pdfIn PDF document text
    • https://www.properties-thassos.com/wp-content/plugins/super-forms/uploads/php/files/qc9j39skchlvuobq8sh52d59cq/78667869849.pdfIn PDF document text
    • https://psychotherapie-dr-albrecht.de/wp-content/plugins/formcraft/file-upload/server/content/files/1608a11c8c408f---sefuwobalopeliv.pdfIn PDF document text
    • http://titadoorbinhduong.com/upload/files/77943093179.pdfIn PDF document text
    • https://promocionesnma.com/wp-content/plugins/super-forms/uploads/php/files/50ab319988314014ac47e22f8528241d/19536386531.pdfIn PDF document text
    • http://goksirkrupskimlyn.pl/img/upload/files/70737559699.pdfIn PDF document text
    • https://www.avenueroadadvertising.com/wp-content/plugins/formcraft/file-upload/server/content/files/16084061b571ad---visewatun.pdfIn PDF document text
    • http://dungcubepgiangtrinh.com/webroot/img/files/21133623834.pdfIn PDF document text
    • http://foodchemsino.com/d/files/buris.pdfIn PDF document text
    • http://hellnocancershow.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608436b2efbab---18118944156.pdfIn PDF document text
    • http://apricomm.com/userData/board/file/34648531180.pdfIn PDF document text
    • http://big-blue-bus.com/pics/fotos/1/file/lexexibozekubixesug.pdfIn PDF document text
    • https://teenvolunteer.org/wp-content/plugins/super-forms/uploads/php/files/ca1bfa42160869a9c71b7515cf78a145/8798161323.pdfIn PDF document text
    • http://www.christinemartin.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/1607821783eaba---71344621456.pdfIn PDF document text
    • https://ladychief.com/wp-content/plugins/super-forms/uploads/php/files/b7bcf2556567713938b11ca356601242/75525725762.pdfIn PDF document text
    • http://aimic.com/userfiles/file/81030375504.pdfIn PDF document text
    • http://qca.ch/userfiles/file/kigadakofovaxeduji.pdfIn PDF document text
    • https://gauravkankariya.com/wp-content/plugins/super-forms/uploads/php/files/rpbpaksk1cgeu3q96begd2uca4/23165661278.pdfIn PDF document text
    • http://bukharasuwanee.com/sites/default/files/file/xujukif.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/A3Ryygt5BCM/uplcv?utm_term=convert+pic+in+to+pdfPDF 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_off0000cf59.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCF59 10336 bytes
SHA-256: f67a9f6c90496ed691d2219fde83633ee32ab2eb3c7a5fb4629096d002bbcc01
font_01_sfnt_off0000e6cf.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE6CF 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000fee1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFEE1 17440 bytes
SHA-256: b7d78447c273a5e5663bffddc38eb26aed59bc266ab61da3d549672da8529d8e